The Demon King pleaded

"Onee-chan."

"...Again! Eiji-chan! Call me Onee-chan again~!"

Serafall was excited, but what greeted her next was the pain in her ass.

Not knowing what magic Eiji used, she suddenly fell to the floor.

"Wooo! Eiji-chan, how could you do such a cruel thing to your future sister-in-law?!"

The magical girl had an almost tearful face, looking pitiful, but Eiji knew she was pretending.

I mean how could one of the Demon Kings in the underworld, Serafall Leviathan who had survived many battlefields in the past would cry just from falling to the floor using her ass?

"Just now I did it. Isn't that proof? Want to try one more time? This time I'll use a bit of my strength."

[Exactly 20% of my physical power is enough to throw a mountain. I wonder if the Demon King's ass can withstand my slap? I suddenly want to try it.]

"No! Eiji-chan, you don't have to." Serafall shuddered, she hurriedly got up and looked at Eiji while covering her ass as if wary of something.

Who would want to receive your slap? Although it was only 20%, Serafall remembered the physical power Eiji had shown when beating Diodora back then.

So she knew how terrifying Eiji's physical power was even though it was only 20%.

If she received Eiji's slap on her ass, she was worried that her plump butt would have red hand prints that wouldn't disappear for days. And that still didn't include the pain!

"Is that so? Too bad." Eiji sighed as if disappointed, but secretly he was actually surprised by what Serafall was wearing.

It was not like usual where the woman would wear a dark green suit or her magical girl outfit. Now she was wearing a girl's school uniform! It was the same uniform that the female students at Kuoh Academy wore.

A white long-sleeved button-down shirt, a black ribbon on the collar of her shirt worn under a black shoulder cape and matching button-down bodice, a magenta skirt with white accents, and brown dress shoes over long white socks.

That woman transformed into a high school girl!

With a short yet voluptuous figure, especially with her large breasts and double pigtails.

Her extremely beautiful and cute appearance illuminated the corridor they were in.

[What is this woman doing? Serafall, don't tell me you suddenly want to go to school here? That's not funny at all.]

Seeing Eiji staring at him expressionlessly but Serafall could see the boy's gaze staring at him without blinking.

There was also his curious inner voice.

Serafall felt proud of her appearance, she smiled seductively and said: "Eiji-chan, what do you think? Levia-Tan in school uniform is very pretty and cute, right?"

"Ordinary."

"Mou~ You're so dishonest. Are you curious why I'm dressed like this? If Eiji-chan calls me Onee-chan again, I'll answer him!"

Calling you Onee-chan again? A big guy like me? It's honestly a bit embarrassing.

Eiji rolled his eyes, forget it. He turned around and continued walking. But how could Serafall just stay still? He certainly followed the boy and walked beside him.

"Nee Eiji-chan~ Hey, did you hear me?"

"....."

"Aren't you curious?"

"...." Eiji continued walking without answering, at some point he looked out the window instead of paying attention to the beautiful woman walking beside him.

Serafall frowned at this, from Eiji's indifferent attitude towards her, she knew the boy still seemed to have some dissatisfaction with her.

But why, is it because she still hasn't kept her promise?

This boy is so vindictive! Though if you think about it, back then she had given him a little compensation in the form of letting him play with her ass.

Recalling what she felt at that time, Serafall's cheeks flushed slightly, her gaze couldn't help but fall on Eiji's hand.

What she called the reason for coming to this school was indeed to meet her younger sister and Eiji.

But that was not all, she was actually here to satisfy her curiosity about the "male touch" that Eiji had mentioned back then.

She didn't want to admit it, but since then, she kept thinking about how it would feel to be touched more by Eiji.

[Curious? It was actually not hard to guess why Serafall was wearing a school uniform. If she didn't join the school as a student, she must have been just idly wearing a school uniform similar to her younger sister's.]

[In short, she's just cosplaying and it seems like this is also her plan to seduce me. Let me guess, this woman still hasn't given up on joining my harem in order to be with her younger sister.]

You know?

Serafall looked at Eiji who continued to walk while ignoring her, she sulked and wondered why that boy could always guess what she was doing.

Earlier the boy could guess she wanted to join his harem because her younger sister was also there.

And now he also knew the reason why she was wearing a school uniform was to seduce him!

She admitted she still had ideas about her little sister, but she also felt quite fond of Eiji, okay? So wasn't that fine? In the future they could play together in bed.

There were also other beautiful women like Rias, Akeno and others. Imagining those things, Serafall almost drooled.

If Eiji knew what Serafall was thinking, he would...

[Ding!]

Well he already did.

Serafall blinked her eyes in confusion.

"Eiji-chan! Eiji-chan! Look, what's this?"

While walking, Eiji frowned and said: "What? I don't see anything."

"How could you not see the pink screen floating in front of my face?"

[Is this one of your tricks to seduce me? Serafall, you disappoint me. If you can't even seduce a man, don't think I'll accept a yuri like you in my harem.]

You said that again...

Serafall bit her lip, her smile almost broken at hearing Eiji reject her in his heart. There was a hint of hatred as she looked at the boy.

What's wrong if I'm a yuri? Now that a woman like me has even taken the initiative to seduce you, do you really hate the idea of me joining your harem?

Serafall was dizzy, she thought Eiji was too possessive. But what could she do? How she could get the boy to agree to accept her, she didn't know...

By the way it seems that only she can see the pink screen floating in front of her face. As a woman who loves watching Magical Girl anime, she must have also watched other anime. One of them is an anime where the protagonist has a golden finger called a system that looks somewhat similar to the thing in front of her.

Wait, is this really that thing?!

Serafall tried to check the magic energy contained in that thing and tried to dispel it, but she couldn't feel anything from it. She was a little panicked, the thing that worried her was that this was something sent by her enemy.

Although the Three Factions had made a peace treaty, there was still another Faction that might make a sneaky move to kill one of the Demon Kings that was visiting the human world.

Serafall was wary.

[Host, calm down. Your guess is correct. I'm a system, but I'm not something sent by your enemies. I won't hurt you. Instead, I'll help you get Destiny Child's heart!]

Destiny Child? Who? You mean Eiji?

Also, why should I trust you?

Serafall had many questions, she naturally knew that she seemed to be able to mentally communicate with the female voice inside her head.

Was this what it was like to have a system? She felt a bit crazy for talking to the voice inside her own head.

But she was also a little excited that something that usually happened in anime was actually happening to her.

[Yes, Eiji Seiya is Destiny Child. You can call him the protagonist. There are also other protagonists in this world, but compared to him, they are all just his stepping stones and will be slapped if they want the things he wants.]

About slapping the protagonists. Serafall felt that was exactly what Eiji was doing, after all, she knew that the boy had slapped several protagonists and made their women his own.

So besides being a time traveler, Eiji was also actually a protagonist? No wonder he was so powerful and had a harem filled with many beautiful women.

Serafall felt this information was trustworthy, but that didn't mean she really believed in the system that suddenly appeared and said it wanted to help her.

That was too suspicious.

[Your suspicions are reasonable. As expected of the host I chose. Actually the reason I bound myself to you is also because it just so happens that your current situation is very suitable for me.]

'Suitable? How does my situation suit you?' Serafall asked in confusion, she did not sense any danger from this system, so she did not mind trying to chat with her first before taking action.

...

Serafall became more reserved and her gaze continued to stare ahead as they walked together.

One might be confused as to why the woman who had been cheerful and very noisy suddenly became quiet, but Eiji knew the reason why Serafall became like that was because she was busy talking to someone inside her head.

To be precise she was now talking to the system he had just given her without her knowledge.

Eiji smirked, he had spent 5000 system points to create another Sub-System. Unlike before, this time he tried it on the heroine and that was Serafall.

Serafall's arrival required him to change his lunchtime plans. So he went to the cafeteria, bought some snacks and went to the roof of the school.

But as he climbed the stairs to go to the roof, Serafall who was still following him from earlier finally spoke.

"Wait a minute, Eiji-chan! Can we spend a moment here?"

"Here? You mean you want to eat on the stairs?"

"N-No. Not to eat, Eiji-chan... Are you so hungry?"

"Not really."

"Then will you do something else more fun like..."

"Do what?" Eiji pretended to be confused, he was still staring at Serafall who was hesitant to speak.

There was shame in her pink eyes, but Eiji could also see the humiliated expression on her face.

He had trouble holding back a smile seeing that.

Yes!

This is it, this is it, come on Serafall! Rather than seducing me in a clumsy way, it's better for you to do something more daring without caring about your dignity.

I like seeing a proud woman like you humble herself to get a man.

Has Serafall been arrogant all this time? On the surface no, she was a cheerful woman and did not hesitate to hug the people she liked like a big baby.

But Eiji knew, if Serafall was really serious about giving herself to him because she really liked him. She wouldn't seduce him slowly, she definitely wouldn't hesitate to offer her body to him considering her promise that she had broken many times.

So far, she had always hesitated and seemed to prefer to make him fall in love with her first and let her join his harem.

Although she always thought of herself wanting to be touched by him, but she did not want to beg him for it.

She wanted him to beg her for it because her pride would not allow her to beg someone to molest her.

After that, she would be willing to do it with her younger sister, Sona and possibly other women in his harem.

In the end she is still after his own women.

It wasn't that Eiji hated Yuri. Well... Maybe a little, he just didn't like his own women not thinking single-mindedly of him. He realized he was too selfish because he himself wasn't single-minded. He had a harem after all.

But he...

¶{Host, please stop there. We'd better get on with the plot.}

Cough, Miss System is right. So Serafall, what did you want to say?

Although Eiji already knew because he was the one who created the system for that woman, he certainly knew what quests the system gave her.

He was just curious if Serafall was really willing to do it?

"I... Eiji-chan, I actually want you to..."

This was the first time Serafall had such a hard time saying anything. Usually she was shameless, loving to show off her voluptuous figure in magical girl clothes to everyone, she was not shy about showing her excessive affection for her younger sister, and she was also not shy about screaming like a little girl in public.

But now...

She felt ashamed... and humiliated...

As a Demon King who inherited the name Leviathan, it was a lie that a woman who liked magical girls like her was not arrogant and had her own pride.

And begging someone to do those things to her was...

[Host, time is running out when you think so much. This is Destiny Child! You don't have to feel ashamed or humiliated for begging him.]

Is this what person say? No, it's just shameless artificial intelligence!

How could you do this to your host? So what if it's Destiny Child? You said you wanted to help me? Is this what you call helping?

Serafall complains, she complains a lot about the golden finger she just got a few minutes ago.

The reason why this system chose her out of everyone, she said it was because she was the one who tried to seduce Destiny Child (Eiji) but had trouble because the boy's attitude towards her was too indifferent. So the kind system took pity on her and wanted to help her.

Wow... So kind like the holy mother. Even Serafall, how could she believe such elementary school level reasoning? But the system proved herself!

It gave her a starter pack. Serafall who loves watching anime is also familiar with the term.

So she gained another ability in addition to the one she already had as a devil. She now had the ability [Eyes of Love]. It was a rather embarrassing name, but with this ability, she could now see the affection that others had for her.

For example Eiji.

[Favorability: 20]

Can you believe it? Serafall suspected this ability to miscalculate numbers. How could this pervert boy who had played with her ass, glanced at her breasts several times, and pretended to be cold to her have such a low liking for her?

Unfortunately the system said it was true.

Serafall was not sure, but when thinking of Eiji complaining that he could not possibly accept a yuri in his harem. Was it because of this? Because she was yuri?

[Start counting down before your little secret becomes known to your little sister.]

[15]

[14]

Ah!

Serafall was getting panicked, and the most annoying thing about the thing that said she wanted to help her was. The system is helping her but it's also threatening her!

If not for the fact that failing the mission would have meant exposing her little secret to Sona...

Of course, Serafall knew what secrets she had. And the system had convinced her that she knew all of her dark matter.

The other party used her sister's reaction to learning her secret as a threat.

Damn!

If not for that, Serafall was very reluctant to try to complete quests from the system.

Although the rewards were also very tempting.

"...." Eiji wondered how long he had to wait? Soon the lunch break will end.

"Eiji-chan!"

"Yes, I'm here."

Finally! Serafall, say it!

Serafall whose face was flushed, her gaze that was originally looking at Eiji's face slowly dropped to his pants.

"Please! Can you take off your pants? Onee-chan wants to play with your little brother!"

..

A/N: If you want to read 8 advanced chapters with a faster update frequency than the webnovel, you can read it on my patreon whose link is below:

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