Prologue: Parallel World in Real World.

Today was August 28th, and the sky was clear.

High school student Kamijou Touma was awakened from his slumber by a girl's voice yelling, "Oniichan~!"

"What was that shrilly voice just now?"

Kamijou, still half-asleep, slowly opened his eyes. The blanket that should have been covering his body was crumpled at his side.

The source of the voice was beyond the door.

His glance sideways revealed a six-tatami-mat-sized Japanese room. Worn-out tatami mats stretched out along the floor. On the ceiling was a fluorescent lamp covered with an old square covering for electric lamps. The wooden door was layered with specks of dirt and had a simple lock, the type that looked like one commonly used at toilets. A discolored yellow electric fan ventilated the room instead of an air conditioner. He breathed in deeply, and smelled the scent of the sea.

This was not the room in his apartment, nor was it a place in Academy City.

This was a guestroom on the second floor of a beach lodge named Wadatsumi, located somewhere in a certain sea coast within the Kanagawa Prefecture. Kamijou's parents and Index each had a separate room.

"Ah, yeah, we're already outside."

Kamijou concluded with a half-functioning brain.

The Academy City where Kamijou normally lived in lay in the western part of Tokyo. Therefore, those people who were used to living inland might love the idea of going to the seaside (though they could still enjoy the waters if they go to the fishery schools, but not much).

As a countermeasure against abduction of students (samples) by a possible agent or spy, leaving the premises of Academy City was strictly prohibited. To leave, the student must first write up and turn in three written applications. After signing all of them, their blood has to be checked for authenticity of identity using a micro machine, and lastly, they need to have a guarantor to obtain a complete pass. However...

(I'm here right now.)

Kamijou stroked his right hand. The mark made by the mosquito needle that was used to draw his blood was barely noticeable even when touched.

Normally, the student was the one who'd beg the teachers for permission to leave, which somehow went like this: "Sensei, please allow me to leave~" However, it was a special case this time; the teachers actually ordered Kamijou to leave, like this: "Get out of the city, idiot!!"

Last week, Kamijou had defeated the most powerful Level 5.

The rumor regarding the denouement of battle had spread like wildfire despite the sparsity of students during summer break. With that, one might think that Kamijou's position had improved—but in reality, it had been the reverse.

"I see! If we defeat that Level 0, we can have Academy City's title of the strongest esper!" Because of that rumor, the town delinquents had gathered, and had gone after Kamijou, starting the game of survival hunt.

The higher-ups, frazzled by this rumor, had contacted Kamijou, and said, "Hey, Kamijou Touma-kun, we'll handle the matters here by manipulating information, so in order to not cause any unnecessary uproar, can you go someplace else until the dust is settled?"

(They said that, but they were clearly showing their contempt by sending me here to a rundown lodge.)

Kamijou let out a big yawn. Even though it was summer, due to the outbreak of large jellyfish apparently inhabiting the waters near the shore, the number of customers visiting the place was close to zero this year. Putting that aside, leaving Academy City required accompaniment by a guarantor—in this case, his parents. Never mind if they were cute girls or sexy older women, but why would someone spend their precious vacation time with their parents at this age?

For Kamijou, everything would be fine if things were just this simple.

The upshot of defeating the strongest Level 5 had forced a big project to be terminated. Some of the higher-ups might have borne a grudge against Kamijou. Fortunately, thanks to the recent rumors, they could not take action immediately; the reason was that if they even thought of doing so now, it would be disclosed to the public immediately.

However, the still half-asleep Kamijou didn't feel even a fragment of uneasiness.

(Uhhh, I'm still sleepy... Is everyone up now?)

He absentmindedly recalled the sister in white that was supposed to be sleeping in a room across his own.

(Maybe she's still enjoying herself in dreamland,) he thought.

The sister in white would probably be filed under the "cute" category. Still, imagining himself shouting deep inside, "Thank you very much for the nice summer!" with tears of joy after seeing her childlike body in a swimsuit would be abnormally ridiculous.

He had been surprised at the sight of Index, who nervously came out of the fitting room after trying out the swimsuit they had bought in the supermarket—not to mention that he'd also been surprised at the number of zeroes written on the price tag.

For your information, the white sister had no plans to tag along in the first place; she was supposed to stay in Academy City. Kamijou had planned to leave her—and her cat—in Komoe-sensei's custody. The swimsuit that they had bought was originally prepared for use in the school pool.

After reflecting upon it, it had naturally been the best choice. However, that white sister was not one of the students enrolled in the city; in other words, she was an outsider. That airheaded sister might be spotted and caught by Anti-Skill. That said, Kamijou still had no way to make her a pass to leave the city.

But the sister in white had not cared one bit about that fact. Kamijou had given up when he had seen a crying Index after she had been told to stay home.

As a result, he had tried smuggling the sister out of the city.

To put it simply, they had just needed to call a taxi, let Index hide in the rear seat or compartment, and wait until they got past the gate. Kamijou could not believe that he had considered carrying out that cheap method. However, things didn't really go his way; they had been stopped at the gate. It seemed that an infrared seeker and a MRI scanner were used to monitor the vehicles passing through.

(Oh, no, we're gonna be caught,) Kamijou had thought on tenterhooks. However, they had not actually been arrested; it appeared that Index had been registered as a guest with a guest ID.

Both Kamijou and Index had not known about that.

(I wonder who registered Index?)

The registration of a person required three things: fingerprints, a voiceprint, and retina patterns of that person. Well, voice and retina patterns could easily be forged by using a high resolution video camera, and even fingerprints could be duplicated by using either aluminum or carbon powder.

But why bother going through all those things?

Kamijou had felt dubious, but it hadn't manifested on his face. He could not possibly do something that would cast suspicion on them. Kamijou had just tilted his head as he had watched the guards restrain Index who had been putting up a struggle against the injection of a nanodevice (a transmission device) into her body (which actually does not hurt at all, thanks to the mosquito needle). They had finally passed the gate after that.

(Uwaa, I'm sleepy~)

He covered his head with a blanket as he drowsily recalled the events. He decided to resume his sleep. His nocturnal habit from summer vacation probably hadn't left him yet. As his consciousness was about to fade into nothingness, he heard the voice again.

"Oniiiii-chaaan, waaake uuup!!"

The energetic call of a girl which came from the hall outside the room penetrated the barrier of the door, and reached Kamijou's ear.

Kamijou thought that maybe there was a useless brother and a reliable sister also staying in the lodge.

(Wait, what the hell is with that enticing combination!? Why do only weird girls like Index or Himegami Aisa flock to my place and not a girl like that?) Kamijou thought stupidly—and then remembered the fact about the large jellyfish outbreak that was driving away the customers. There were supposed to be no customers besides them today.

Then, a loud bang echoed across the room, accompanied by the sudden opening of the door.

(What!? What's happening!?)

Before Kamijou could bring his face out from the blanket, he heard light footsteps approaching.

"How long are you going to sleep, Oniichan? C'mon, get up! Get up! Get up!!"

The voice of a cute girl reached him along with the feeling of a body pressing on his stomach.

"Gwahh!?" Kamijou cried as he felt the shock from the conventional pro-wrestling technique usually seen in manga or dating sims.

Kamijou coughed violently inside the blanket. This was weird; Kamijou Touma didn't have a younger sister.

A soft sensation ran down his stomach, which was partitioned by just a flimsy blanket. Just thinking about which part of the girl was touching his stomach would be enough to make any healthy boy excited, but unfortunately for Kamijou, he was feeling too annoyed at something else to realize that. Kamijou's stomach screamed "Kyaah!" in surprise before rolling onto the floor.

"Dammit, who is it that's trying to disrupt my sleep?"

When he lowered his gaze to confirm the identity of the nuisance...

He found the culprit to be Misaka Mikoto.

"Ouch~ Hey, is that how you treat your sister who especially went over to your room to wake you up?"

The girl, who was wearing a red camisole, landed cutely on her back, and pouted her face in a manner that didn't suit the Misaka he knew.

"Wh—?"

He wanted to say, "What are you doing here?"

Anyway, his drowsiness disappeared instantly.

Misaka Mikoto: an ace student of the prestigious Tokiwadai Middle School, she was one of the seven existing Level 5s in the city. Although capable of discharging high-voltage electricity—and with a cranky temperament to boot—she was also a crybaby. During a certain incident, Misaka owed Kamijou a debt, and every time he tried to bring that topic up, she would peremptorily assault Kamijou with sparks.

And of course, she was neither Kamijou's genuine younger sister nor stepsister.

Due to his inability to comprehend the situation, Kamijou asked Misaka, "What? Ehh!? Were you also forced out of the city after the Sisters incident? ...Wait, is this some kind of exile island for the congregation of expelled students?"

"Haahhh!? What are you talking about? Is me hanging around you really that weird?"

"Can you stop that disgusting act of fawning? It's been giving me goosebumps for a while now! You're not supposed to be a sister character... You're a tsundere! You should just stick to your proper character."

"I don't understand what you're talking about."

Kamijou felt more goosebumps at Mikoto's apparent nonchalance.

After a moment of being dumbstruck, Kamijou's brain began to fire up.

Hypothesis ①: The authorities ordered Mikoto to pull Kamijou's leg with this canned joke.

Hypothesis ②: Mikoto decided to play the sister role (stepsister setting: on) upon Kamijou as an act of repayment.

Hypothesis ③: One of Misaka's clones for some reason or other had a glitch.

(I'm sure it's ①; there's no way it's ③. I know that Misaka's clones are sister characters. If that's the reason, that would be nice—no, there's no way I'd have a fantastic flag like that. But what if... what if it's ③?)

...

...Ohhh.

"Ha!?"

Kamijou returned to reality after a few seconds of reverie.

Shaking off the fantasy that summer had showed him, he shouted, "Idiot! Don't make fun of a high school student!! Do you think a middle schooler like you can bewitch me with that technique!?"

"Oniichan, you've been hyper ever since this morning."

"Dammit, stop lumping me into the 'happy to be called Oniichan' category! First of all, why are you calling me Oniichan!? And is that coming from a true incest setting or a false one!? Goddammit, I can see where this is going!! It's probably the latter, right? With a plot twist revealing that they were actually blood-related in the end stopping the possibility of the route! I'm pretty sure it is!"

"Haah, I wonder what language you're speaking in? That double dutch? Anyway, who cares about whatever I call you? I'm calling you Oniichan because you're my Oniichan."

"No, I'm not! Why are you my younger sister!?"

"Hmm?"

Mikoto poked her cheek with her own index finger as a sign of puzzling countenance.

"Does me being your younger sister necessarily require a reason?"

Mikoto heaved herself up from the floor.

"C'mon, now. If you have that much energy, then get up. Afterward, come down to the first floor for breakfast," Mikoto said nonchalantly, and left the room.

"What's happening here?" Kamijou muttered while gazing at the exit of the room.

(...Ummm. In the end, what was that all about?)

Unable to grasp what was happening, Kamijou changed into his casual clothes, and left the room.

Outside his room was a short rectangular hallway. Abutting its lengths were three doors belonging to guestrooms—six in total.

The wooden floor was black like that of an ancient temple, and particles of dust and sand were scattered randomly on the surface of the floor, which would cause anyone walking on it barefoot to feel disgusted.

The stairs were located at the end of the hall.

That was Kamijou's destination when he heard the door open behind him.

"Morning, Touma. Hmm? Your hair's disheveled at the back of your head."

It was the voice of his father.

Kamijou Touya. His age was somewhere around thirty. This middle-aged man, with a beard in the form of stubble, somewhat resembled Touma. His occupation in the exporting business had him leave the country thrice every month. His appearance was probably influenced by his job, as he looked intrepid yet somewhat intellectual.

Kamijou, who had lost his memory, did not remember the face of his father, so he had no way of attesting whether or not that person really was his father. In contrast, his father approached him without reserve.

To a high schooler, a college student who was two or three years older than them was already "a different person living in an unknown realm with a different lifestyle". Much more to a person with a significant age gap, Kamijou had no idea how to behave in front of him.

"Un~ Morning... eh?"

As he turned to greet his father, Kamijou's face lit up in astonishment.

"What's the problem, Touma?"

Kamijou's father, Kamijou Touya was knitting his eyebrows.

But let us put that Kamijou Touya aside first...

Kamijou cast his glance to the source of the anomaly, who was standing beside Touya.

"Index, what's with that appearance?"

Yes, the girl standing beside Touya was a silver-haired foreign girl with green eyes.

If you asked Touma to describe Index, he would just simply say, "She's a girl in sister dress." However, Index was not wearing her usual outfit today. Even though it was hot, she was wearing a flimsy half-sleeved one-piece dress that stretched down to her ankles. Draped around her shoulder was a cardigan, and on her head was a big white hat (tsubahiro). Let's be frank: she did not look like a healthy girl at all. He was about to ask her which sickly character she was or which country she was from when he suddenly remembered vaguely that his mother, Kamijou Shiina, had the same kind of attire yesterday.

Shiina's hobby was paragliding. One time, in a park near their old house where a public exhibition was being held, she had sat on a swing-shaped parachute with a motor engine on her back that ran the propeller. There was a report at that time stating that local people had witnessed the sight of a flying wife in the sky.

"Where did you get hold of that dress?"

Touya, confounded at Kamijou's odd question, asked instead, "Touma, is there a problem with your mom's dress?"

Kamijou eyed Touya with a "What!?" expression.

Touya turned his face to the girl beside him, and confirmed, "Yeah, it's your mom."

Kamijou returned his gaze to the girl. No matter how you look at it, she had the appearance of an airheaded foreign girl of fourteen years or less.

"Eh? Wait, Father, don't tell me you see this girl as Mom?"

"Is there anyone you're seeing besides that?"

"Wait, just wait a minute! I'm having a hard time comprehending this joke—if it really is a joke. If you're intending to continue performing this joke up until the end, I have no idea how to respond."

"Touma, tell me which part of your mom has a problem."

"Everything! Firstly, her appearance doesn't even look like that of a mother at all!"

Kamijou pinched the cloth that the fourteen-year-old girl was wearing.

"My, my, Touma-san, are you saying you don't like my sense of fashion?"

"Stop that, Touma, you're making Mom sad with that (worried)."

"No! I mean no matter how you look at it, she's younger than me! Even if this is a theatrical play intended for elementary students, she can't even pass as a high school girl that's already a mother!"

"My, my, Touma-san, are you saying I appear younger than my age?"

"Stop that, Touma, you're making Mom happy with that (jealous)."

"Aahh, geez!" Kamijou cried while burying his face between his palms.

Kamijou knew it. The first time he had seen Touya and Shiina was a month ago in a hospital, after he had been hospitalized for a head injury. At first, he had doubted them when they had told Kamijou that they were both almost the same age. Kamijou knew that his mother looked like an elder sister in her twenties.

But no matter how young his mother looked, Kamijou would not be convinced that his mother was a fourteen-year-old girl.

"Why are you suddenly burying your face between your palms, Touma? Are you already experiencing puberty-related problems? In that case, I have a souvenir here that I bought during my business trip. It's an amulet to ward off trouble."

"No thanks. I don't believe in amulets or any other superstitious stuff. I'm pretty sure it's just an ordinary product mass-produced in a factory somewhere... Eh, what's up with that palm-sized stone statue? It has the shape of male genitalia no matter how you look at it."

"Ahaha, I think so, too, but it somehow looks like an occult amulet."

"What protection does it provide? If I try keeping this thing as a replacement for a cell phone strap, not only will people think that I'm a freak, but I'll also be arrested!"

"What, Touma? A souvenir from abroad doesn't suit your taste? In that case, here's one that I bought from Akita."

"What is it this time...? Uhh, it's shaped like male genitalia again! This time, it's crafted from wood. Are you an elementary student who likes dirty jokes!?"

"Mmmu. Come to think of it, my co-workers had roared with laughter when I brought this to the office on the day of my return."

"Why are you pretending that you have unknowingly ventured to the realm of sexual harassment, you idiot father!?"

Because of Kamijou's sudden unexpected behavior, Touya made a perplexed face and asked, "By the way, Touma. The lady with you, is it alright not to wake her up?"

"I'm already telling you, she's there beside you! Never mind that; tell me where Mother is!"

"My, my, Touma-san, you prefer to treat me not as a 'mother' but as a 'lady'?"

"I'll slap you with a paper fan if you say anything more than that!!"

At that moment, the door beside Kamijou opened.

"Look, Touma, you woke up your friend with your commotion."

"Index?"

Kamijou turned to look at the direction of the door.

The person that appeared from the room, clad in sister suit, was a blue-haired guy with an earring pierced in one ear.

A tall man with a height of 180 centimeters. He was wearing Index's sister suit, though he appeared to have not donned it forcibly. Kamijou didn't know where he got the clothes, but it appeared to have the exact design in an extra-large size fitting his tall body.

The tall man said in a sonorous voice, "Fwaahhh, hmm? Touma, you're full of energy early this morning. Did something happen?"

...Ah.

The big man was acting in a cute manner.

"I know it's late, but good morning, Touma. Anyway, the sea! I thought Japan's sea was concrete fortified with oil floating on water, but it's actually pretty. Mmmphhh, okay, I'm ready to play!"

"Ahhh..."

The big man inadvertently peeked at Kamijou's face from below.

"Hmm? What's wrong, Touma, suddenly looking petrified? Ah, don't tell me you're already fantasizing about my swimsu-"

"Aaaaaaaaaaaaaaaaaaaaaaaaaaaaaaaahhhhhhhhhhhhhhhhhhhhhhhhhhhh!!!"

Finally unable to withstand it, Kamijou grabbed the blue-haired man together with the door, and... *Bam!* The sound of the big man being thrown inside the room, followed by the violent slam of the door closing, reverberated through the hallway.

"T-Touma! Sit there in the corner. I'll preach to you not to treat girls in a brutal manner!"

"My, my, Touma-san, I didn't know that you have a violent passion towards girls."

Touma ignored the apparently flurried Touya and the fragile-looking Index and started reflecting.

(Calm down and think, Kamijou Touma. This must be a wide-scale prank. I don't know what Aogami Pierce is doing here outside the city, but if I keep making reactions like this, then that's exactly like falling to their plan.)

Ignoring his parents, who were worried about the man claiming to be Index, Kamijou made his way down to the first floor.

He thought, (I don't have time to play along with your prank.) But in reality, he was just too hungry and had no energy left to keep up with them.

Kamijou descended the narrow wooden stairs.

The first floor of the Wadatsumi lodge was built from wood and spanned a large area. Due to the absence of a door or a wall in the entrance and exit of the lodge, the sea breeze directly blew through it.

The self-proclaimed "younger sister", Misaka Mikoto (aka Biri Biri) was sitting at one of the tables (or was it a low tea table?) that were interspersed around the middle of the room. She was idly reading through magazines. Under the table, her feet, extending from her short camisole, were kicking back and forth. Her face clearly displayed extreme boredom. There was a TV nearby, but it was turned off.

Kamijou put on an annoyed face.

"Hey, Biri Biri, why are you sitting there as if it's natural for you to be there?"

"What, Oniichan? Are you still mad about earlier? It doesn't matter, does it? Whether I hug you, cling to you, or flirt with you?"

"..."

It seemed that she was intending to keep up this fawning act to the end.

"Uuu... I feel like a fool for going through all this trouble to leave the city."

Kamijou sighed heavily out of mental exhaustion. Mikoto sighed, too—out of boredom, though—closed the magazines, laid herself on the floor, and started rolling around.

"Ah, by the way, Oniichan, can I watch TV?"

"W-what is it, all of a sudden?"

"Mmmu, I can't find the remote anywhere. This TV has a 'This is for public use, so don't monopolize it, shorty brat' aura to it, so that's why I'm hesitating to turn it on myself without permission, Oniichan."

"..."

Kamijou clutched his head at Mikoto's persistent sister act.

"And why would the arrogant and self-centred Mikoto-sensei restrain herself from using the TV?"

"Mikoto? Who's that?" The Level 5 seemed to feign ignorance. "Anyway, I'm not really restraining myself; it's just that the owner of this lodge is scary. Oniichan, go ask him for permission to use the TV."

"...Correction, even if you change your character, you're still arrogant."

Even though he said that, Kamijou had a habit of watching TV during mornings, so he found himself uneasy if didn't watch it.

(Where's the owner?)

Kamijou scanned the place nearby. There was no one at the counter. Kamijou tilted his head as he pondered about the inattentiveness of the staff when he suddenly smelled a burnt-like aroma of soy sauce wafting in from the exit.

(???)

Kamijou directed his attention to the exit. A slender and tall man was grilling something a small distance away from it.

"Ah, that's the owner. C'mon, ask him about the TV!" Mikoto said as she flapped her feet under the table.

Kamijou found it odd. True, the owner of this lodge was a tall and gruff man, and he may look intimidating at first glance. But was his hair originally shoulder-length- and on top of that, red in color?

Kamijou walked towards the man, creating creaks from the wooden floor with his footsteps.

"Excuse me."

The red-haired man turned to face Kamijou.

Kamijou saw the face of the person that was wearing a T-shirt coupled with half pants and that had a towel hanging on his neck...

...Which turned out to be the magician Stiyl Magnus.

"What the hell...!?"

Kamijou's head finally reached maximum confusion. The Stiyl Magnus that he knew was a red-haired Englishman two metres in height who could manipulate fire at his will to scorch his enemy to death without any compunction.

"Oh, you're up early. The sea is still cold, though—or maybe you didn't get any sleep because of the heat yesterday?"

But the magician that he used to know, fanning as he was grilling the corn, instead said that.

"Oops, this isn't grilled yet, so I can't serve it to customers. Hey, Maou! Come over here and serve our guest breakfast from whatever food that's available!"

The magician wearing beach sandals ordered one of the staff.

(What's happening? What's going on around here?)

Kamijou finally realized something was amiss. That war freak and pro-in-atrocity magician would never participate in this cheesy prank.

Kamijou's mind temporarily froze upon witnessing the shocking phenomenon before his eyes, but he came back to himself when he heard footsteps approaching from behind.

"Dad! You shouldn't say that in front of customers!"

(Who is it this time?) Kamijou thought.

When he turned around, he saw a tanned version of Misaka Mikoto that was wearing dark-purple shorts and an apron standing there.

"What? You have two roles? Ah, no, this one is Misaka Imouto, the clone one."

"Dad, this is a customer, so I should refrain from reacting, right?"

Her face twitched, trying hard to keep her smile from collapsing.

That Misaka Imouto, who was constantly impassive even in the face of death, was unbelievably making an expression of emotion.

(No way! What the hell is she wearing? That's what people call a "naked apron" style! Looking from this side... Uwahh, her tits! For a mere prank, would they normally go this far?)

This time, the original Misaka Mikoto's voice rushed in from inside the lodge.

"Oniiiii-chaaan! Have you asked about the TV? I'm turning it on now~!"

Kamijou peeked inside the house, and saw Mikoto, who was on all fours in front of the TV, turning on the switch. It was probably set up so that a lot of guests could hear it, as the volume was so high that even Kamijou, who was a significant distance away from the TV, could hear it clearly.

"This is Komori reporting live. A jailbreak occurred on Shinfuuchuu prison today at dawn. A prisoner convicted of murder, Hino Jinsaku is currently on the loose, and his whereabouts are still unknown. All middle schools in proximity have been issued urgent orders to cancel all club activities."

The reporter's name was Komori.

Yet the voice that's coming from the TV sounded like Kamijou's advising teacher, Tsukuyomi Komoe.

"Don't tell me...!?"

Kamijou hurriedly dashed to the front of the TV. Then, he saw it: a girl with a height of 135 centimetres and the physique of a twelve-year-old girl gripping a microphone and reading the report.

(What is Komoe-sensei doing there? Is this also a part of their prank? If that's the case, then this must be recorded beforehand? No, this is too real for a prank. Then, a radio wave jacking? For what reason? For the prank? That's weird, the scale is just too big to be a prank so early in the morning.)

Brushing aside Mikoto, Kamijou stood in front of the TV, and pushed the little button below the bottom of the screen to change the channel.

"Oniichan, what are you doing!? I'm eagerly waiting to watch 'Fade in Morning'!"

Kamijou ignored Mikoto who was suing for the rights of the TV. He repeatedly switched channels. Every program in the channel was weird in its own way: the supposed popular sexy newscaster was an old man, and the president of a certain country who was delivering a speech was a delinquent high school girl. Anyway, everything was mixed up and did not make any sense.

But what struck Kamijou as the queerest was the live report. Behind the reporter who was sedately reading the news (this one looks like a truck driver) was a preschool child gripping a large hose, a group of old hags wearing sailor uniforms fiddling with their cell phones, and a Prime Minister that Kamijou frequently saw in the news playing a guitar.

The site of the live report was in front of the train station. Behind the newscaster were throngs of people, and all of them were somewhat mismatched.

(Hey, hey. It's the same no matter what channel I tune in to!)

Even if that was a grand-scale joke intended for April Fools, the stupendous number of extras participating would cost a large sum of money. Moreover, the fact that a Prime Minister was also there proved that the entire story was very ridiculous.

It was obviously not a prank.

(But if this is not a prank, then what is it? Index proclaims herself as my mom, Aogami Pierce is Index, and even Stiyl is the owner of this lodge!)

It was as if everyone, be it inside or outside, had switched places.

If that was so, then what could be the explanation?

Kamijou grabbed his head with both hands. Trying hard to come up with a plausible scientific explanation seemed to be impossible.