Chapter – 42 'Mr. Unknown Variable'

Ryōkū City, Japan, Human Realm

"Nova-Kun, how long are we going to wait like this?" Natsume posed a question as she glanced at the teenage boy with black hair and pale grey eyes at the corner of her range of vision.

"Probably for some time," answered Nova as he too glanced at the same teenage boy Natsume had pointed at a moment ago.

Since it is not a rush hour at the moment when the typical Japanese salarymen return home from their offices after a day of hard work, the train is sparsely crowded, with many seats still vacant. Despite this, quite a few passengers—mostly young ones like high schoolers—chose to stand instead of sitting, finding it rather boring.

Of course, Nova and Natsume were different from these young people—the two of them had firmly occupied two corner seats and were sitting close to each other. Many passengers on the local occasionally glanced in the direction of Nova and Natsume—not because they were dissatisfied with the fact that young people like them were sitting—no, that wasn't the reason at all. Rather, they glanced at the two because they thought that Nova and Natsume were going on a date.

Looking at Nova and Natsume, a middle-aged housewife muttered with a nostalgic smile, 'Ah… young love.' She recalled the days when she was still in middle school and went on her first date. There were many passengers like this particular middle-aged housewife who shared the same sentiment.

Of course, there were also quite a few who felt jealous. 'Damn Ikeman!' These were mostly boys who felt jealous of Nova. After all, Natsume is quite a beauty, and most of all, she has a nice rack size!

Several teenage girls on the train found Nova incredibly cute and handsome. Observing the pretty brunette sitting next to him, they couldn't help but sigh, thinking, 'It's a pity; she seems to be quite lucky. Not only does she get to go on a date with such a cute foreigner, but she also has those…!' These reactions and occasional glances from fellow passengers caused Natsume embarrassment, particularly since they were not actually on a date.

Nova didn't really care about what others were thinking about him and Natsume. To these horny single teenage boys, Natsume may appear quite a beauty–which she is no doubt about it–but to Nova, she is not that attractive. Compared to the beauty of Sona, Lavinia, Tosca, Artoria, and Roygun, Minagawa Natsume is quite bland in his eyes, therefore, Nova isn't really interested in her at all.

Things would have been different if it were Iris Gaule instead of Minagawa Natsume. Nova does find the ashen-grey-haired girl very beautiful, but since she has teamed up with Samejima Kouki this time around, it couldn't be helped.

Putting the misunderstanding of other passengers aside, the real reason why they are on the local train is that they are following one of the other passengers currently present on the same local train.

It's none other than the human who was born with the Balance Braker of [Canis Lykaon] and would go on to become one of the strongest human beings capable of fighting against Gods and Devil King Class beings, the man, the legend, the wielder of 'Dog God of the Black Blade,' Ikuse Tobio!

In order to distract herself from the embarrassment, Natsume suddenly asked with a doubtful expression, "Nova-Kun, in the first place, why are we following Ikuse Tobio-San? Can't we directly meet him and tell him everything about Utsusemi Agency, the truth about the 'Heavenly of Aloha Incident,' and the fact that other students of Ryōkū High School are still alive?"

Natsume's doubts are indeed reasonable, but Nova's hands are tied as Azazel's request dictates his approach. Since Ikuse Tobio is the possessor of the Black Dog, one of the thirteen Longinus and the primary target of Utsusemi Agency, there's a strong possibility that someone significant behind the 'Heavenly of Aloha Incident' might show up to take Ikuse Tobio away.

Azazel's strategy involves using Ikuse Tobio and the other two targets of Utsusemi Agency as bait to draw out their adversaries. While Azazel has a good understanding of the main enemy, having disappeared from the Nephilim Institute about a year ago, he is still uncertain about all the individuals involved. Therefore, using the targets as bait is a calculated move to reveal more about their adversaries.

Azazel's approach, while not fitting the typical image associated with him, is a pragmatic strategy in the context of their current situation. In the complex world of supernatural conflicts, such methods are sometimes necessary to gather crucial information. Among the Slash/Dog team, only Nova and Lavinia are privy to Azazel's broader plans.

The perceived cruelty of Azazel towards Ikuse Tobio and the other two targets of the Utsusemi Agency stems from his pragmatic and indifferent perspective. Having lived for thousands of years and experienced the Great War, Azazel is known as the most Evil Fallen Angel, and individuals he does not personally know may not elicit strong emotions from him. Forming a personal connection with these survivors might change his stance, but until then, using them as bait to uncover the identities of traitors and gain insight into their enemies is a calculated move.

In a similar position, Nova acknowledges that he might have made a similar decision if he were in Azazel's shoes, understanding the complexities of their world and the need for strategic actions.

"Don't fret about it; there are reasons, but I'd rather not delve into them," replied Nova casually, casting a brief glance at the man seated in the farthest corner of the train. Currently engrossed in a magazine, his face remained elusive to onlookers. Judging by his physique concealed beneath a typical business suit, Nova was convinced of his combat prowess. The lingering question was, 'Does his fighting prowess confine itself to normal humans, or does it transcend into the supernatural realm?'

Unless this individual is some deity from mythology, Nova is confident he's human. The quandary lies in the fact that he, too, appears to be tailing Ikuse Tobio.

Nova wasn't sure if the person in question had caught on to the fact that he and Natsume were tailing Ikuse Tobio, but he was pretty certain that this man was tailing the user of Black Dog. Nova had seen him outside the high school Ikuse Tobio attended, walking the same streets and now sitting on the local train, continuously staring in Ikuse Tobio's direction through a small hole in the magazine he seemed to be reading.

'No human with such an appearance showed up in the first four seasons of the DxD Anime, nor was there any illustration of a Caucasian-looking person in his early twenties in High School DxD, Shin High School DxD, or Slash/Dog Light Novels up to where I've read,' mused Nova. Back when he first noticed the man outside Ikuse Tobio's High School, Nova had taken note of his presence. It wasn't immediate suspicion but rather that the man seemed out of place, catching Nova's attention.

A foreigner in his early twenties, tall, muscular, and dressed in a business suit, waiting outside a Japanese High School? Naturally, he'd draw attention, and Nova did notice. Back then, he didn't particularly care, assuming the man wasn't after Ikuse Tobio. Now that it's evident they're targeting the same person, Nova cares.

"He shouldn't be one of the members of Grigori, because if Azazel had sent someone else, he would have definitely told me... same case with Grauzauberer, so these two options can be ruled out. The remaining possibilities are one, someone from the 'Utsusemi Agency'; two, one of the 'Wizards of Oz'; three, someone closely affiliated with one of the current leaders of 'Chaos'; and finally, four, he is not related to either of the first three, which would mean he is an entirely new variable into this equation and belongs to a different faction."

Excluding 'Grigori' and 'Grauzauberer,' as well as the 'Utsusemi Agency,' 'Wizards of Oz,' and 'Chaos,' which are interconnected, the only other faction in Japan linked to the 'Heavenly of Aloha Incident' is the 'Five Principled Clans,' since, the members of Utsusemi Agency are the exiled people of that faction.

For thousands of years, 'Five Principled Clans' have safeguarded the country from supernatural threats, so it wouldn't be too far-fetched to say that they are also targeting Ikuse Tobio. If they are targeting him, their purpose should be to eliminate him since Himejima Clan can not tolerate the existence of someone who is linked to them by blood and possesses the Black Dog, the Sacred Gear which carries one of the Totsuka no Tsurugi said to have killed Hino Kagatsuchi.

Although this possibility does exist, knowing the 'Five Principled Clans' and their strict traditions, Nova doubts they'd allow someone with foreign blood or born within their clans to be associated with a different mythology for such a long time. Even if they did allow it, it shouldn't be possible for that person to live amongst them. Consider 'Himejima Akeno,' 'Shinra Tsubaki,' and 'Nakiri Momoji'—all faced persecution and isolation due to possession of Sacred Gear or foreign blood in their veins.

However, the 'Five Principled Clans' are anticipated to change their ways in the future according to DxD Canon. This is evident from the fact that the next generation of the Yellow Dragon, the next Ōryū Nakiri, plans to take Millarca Vordenburg–a pureblood Vampire from the House of Vordenburg of the Carmilla Faction–as his second wife. Yet, it's safe to assume that these changes haven't been implemented yet, given that leaders like Himejima Suzaku haven't assumed full control of their respective Clans.

For these reasons, Nova is quite certain that 'Mr. Unknown Variable,' with his distinct appearance and height, is clearly not a native Japanese and, by extension, not someone sent by the 'Five Principled Clans.' This indicates he is a foreigner, likely from a faction unrelated to Japan. There's a possibility that this 'foreign faction' is somehow linked to the 'Heavenly of Aloha Incident,' though it's also plausible that this faction has no connection to the said incident.

"I wonder which other faction would want anything to do with Ikuse Tobio," muttered Nova with a thoughtful expression. "Well, whoever this person is, it would be best to remain vigilant until his identity and intentions are confirmed," Nova said as he shifted his attention back to Ikuse Tobio and his new 'friend' from his new high school, who was flipping through a magazine while discussing motorbikes.

Since the two of them were standing at quite a distance, it wasn't possible for Natsume to hear the conversation between the two. However, Nova could perfectly hear each of their words without any problem, a basic ability that all Devils possess. While Nova continued to closely listen to the conversation between Ikuse Tobio and his 'friend,' the topic changed to the 'Heavenly of Aloha Incident.' Soon after, it was time for the 'friend' to leave.

The 'friend' patted Tobio on the back in a cheering manner, then got off the train as it stopped at one of the stations. Now alone, Tobio went through his flip phone, reading old messages sent by his childhood friend, Tōjō Sae before she disappeared/died in the 'Heavenly of Aloha Incident.'

Noting that Tobio was finally alone, Natsume asked in a whispering voice, "Isn't this a perfect opportunity?"

Nova shook his head, "Wait for a while," and prevented the busty brunette from carelessly approaching the wielder of the Black Dog. Azazel wanted to use Tobio as bait to lure out the bigwigs, and considering the presence of 'Mr. Unknown Variable,' who undoubtedly possessed a powerful Sacred Gear, Nova knew he couldn't act carelessly.

Natsume pouted in dissatisfaction but ultimately chose to remain silent and follow Nova's orders. Time passed bit by bit, and soon it was time for Ikuse Tobio to get off the local train. However, for some reason, instead of heading to the nearest station to his home, he got off two stations before that.

As Tobio disembarked, 'Mr. Unknown Variable' folded the magazine he was holding, or pretending to read, as Nova suspected, checked the time on his wristwatch, and exited the train as well.

From his seat, Nova observed Tobio and 'Mr. Unknown Variable' as they got off the train. Natsume looked at Nova, unsure of what to do. Logically, they should also disembark and approach Ikuse Tobio immediately. However, Nova didn't seem too keen on it yet, leaving the brunette confused and waiting for Nova to take action, which he eventually did.

As Tobio and 'Mr. Unknown Variable' walked a considerable distance, Nova suddenly grabbed Natsume's hand, making her yelp in surprise, "Kya!" and blush. She didn't have the opportunity to collect herself or express dissatisfaction before Nova said, "Let's go." Without waiting for her response, Nova led her toward the closing train gate.

The brunette didn't know what suddenly got into her teammate, but she noted his expression and understood he wasn't playing around. He must have a reason for doing what he was doing, so she remained silent and allowed Nova to lead her.

The two teenagers maintained a good pace, and soon after leaving the train, they approached 'Mr. Unknown Variable' and Ikuse Tobio. Noting this, Nova suddenly looked back at Natsume and winked at her, much to the confusion of the brunette. She realized, "Hey... wait, look at the front, we are about to, Crash!" She hadn't had the opportunity to complete her words as they bumped into 'Mr. Unknown Variable.'

Although the bump was sudden and fast, 'Mr. Unknown Variable' wasn't knocked off his feet. In fact, nobody except Minagawa Natsume fell, much to her embarrassment and frustration. Nova apologized with a bow, "I am sorry, sir. I was looking at my friend and did not notice you there. Please forgive me." Then he helped Natsume get back on her feet.

'Mr. Unknown Variable' noticed the people who bumped into him were two teenagers and didn't really mind the small accident. "It's all good, no harm done. Is your friend alright?" He spoke in broken Japanese, the accent clearly American.

While rubbing her butt, Natsume nodded, "Yes... yes, I am fine. Thank you for asking!" She didn't care about the other person's broken Japanese and then glared at Nova, clearly blaming him for the mishap.

Nova ignored the brunette's glare, and after one more bow, he said, "Thank you," once again speaking in perfect Japanese. Then, once again, he held Natsume's hand and led her away from the station.

The Caucasian man looked at the fading back of the green-haired teenager and his brunette friend, shaking his head, "Kids these days..."

…

In a dark alley, Natsume sat, hugging her knees and breathing heavily. After catching her breath, she looked up at Nova, giving him a glare. She wanted to ask him about what he did earlier, but he was busy talking to someone through a Magic Circle, so she decided to wait.

Though curious about their conversation, Natsume couldn't understand a thing.

In a language unknown to Natsume, she overheard, "Governor General, do you have any info on this person? Something that might help me figure out where he's from and what he wants."

He was talking to Azazel. Nova had described his encounter with Ikuse Tobio as well as the presence of 'Mr. Unknown Variable,' to him, and was hoping for Azazel to give him some information about this man.

"I've tried searching using the data you have sent me, but it's too little… only appearance and that's not much, as such so far there are no results. All I know is he's not from Grigori and had no connection with us since I founded the organization, and Mephisto confirmed he's not with Grauzauberer either, and had nothing to do with them. Figuring out exactly where he's from based on appearance alone is a bit tricky," Azazel answered casually.

"I see," muttered Nova, not disappointed as this aligned with his expectations.

"Do you have any other information on him?" Azazel inquired.

Nova pondered for a moment, responding, "Well, he had an American accent. Maybe if you check the data on all the U.S. natives, you might find something."

"We could do that, but there are about One Hundred Fifty Million men in the States. Checking and matching each person's appearance with this Caucasian man would take at least a few days, and that'd be too late," Azazel sighed.

Nova nodded, "I guess that's true." After a brief pause, he asked, "So, what do you suggest I do?"

Azazel advised, "I'd recommend you continue what you were doing. If 'Mr. Unknown Variable' interferes, just capture him using your 'Time Prison' and bring him to me. My people will question him and figure out his intentions, and his background."

"Might be a little tough since 'Mr. Unknown Variable' seems pretty strong. I'd say he's definitely stronger than a high-ranking Devil... If it's just him, no problem, but if there are others, it could get a bit tricky. I might get distracted, and the lives of Minagawa Natsume and Ikuse Tobio could be at risk," Nova explained.

"I see, that is indeed a cause for concern. Honestly, I'd prefer to send one of my direct subordinates, but until we confirm things, I don't want to reveal ourselves openly..." Azazel mused. After some thought, he suggested, "I guess there's only one thing to do—call your [Bishop] to your side. With Demise Girl there, you shouldn't have any problems. You can let loose without worrying about Minagawa Natsume or Ikuse Tobio, and she'll be able to protect them."

"Are you sure?" Nova questioned with doubt in his tone. "What about Nanadaru Shigune?" He was aware that with Lavinia at his side, he wouldn't need to worry about Minagawa Natsume and Ikuse Tobio. However, Lavinia and Vali had gone in search of Nanadaru Shigune. If Nova called her to his side, it would leave Vali alone.

"I'll leave that to Vali; he should be able to handle things there even if he's alone," responded Azazel.

"Very well then," Nova nodded. Since Azazel expressed confidence, Nova had no reservations. Besides, trusting Vali's capabilities, Nova believed he could manage. Additionally, with [Albion] by his side, the Vanishing Dragon would guide Vali if necessary. Moreover, Nova wasn't immediately calling Lavinia; he would only do so if the situation demanded it.

"Alright then, I'll continue to investigate the background of 'Mr. Unknown Variable.' Meanwhile, you focus on your tasks," said Azazel, prepared to end the call.

"Understood," Nova nodded, and with that, the communication circle dispersed. Now that the call was over, Natsume inquired, "Who were you talking to?"

"The Governor," Nova replied. The identity of Azazel hadn't been revealed to Minagawa Natsume and Samejima Kouki yet, so whenever Nova and the others discussed Azazel, they referred to him as the 'Governor.'

"I see," Natsume nodded, accepting Nova's response, and then asked, "So, what are we going to do now? Are we still following Ikuse Tobio? Wait, but... we don't know where he is at the moment, thanks to a certain someone. What got into you earlier?" She was referring to why Nova had suddenly taken her hand and led her away from the train station.

Nova shrugged, "I needed to do that to place a Tracking Spell on that Caucasian man."

Natsume narrowed her eyes, "You mean the person we bumped into at the train station?"

Nova nodded, "Yes... that collision wasn't an accident; it was intentional."

Natsume was taken aback. "I... I see," but she was also confused. "But why would you want to put something like a Tracking Spell on a stranger?"

"Because he has also been following Ikuse Tobio," answered Nova.

Natsume's eyes widened. "Following Ikuse Tobio-San?"

Nova nodded. "Indeed," and created a Magic Circle in his hand. A geographic radar-like hologram appeared with two distinctive red dots. The red dots slowly moved through the streets.

Observing the dots, Natsume murmured, "One of them is that person, while the other is Ikuse Tobio-San?"

Nova nodded. "Yes," and added, "With this, we know where the two of them are at any given time." Nova had also placed a 'Tracking Spell' on Ikuse Tobio using the small window he had when he passed by him at the time Tobio and his 'friend' were on their way to the Local Train Station after the school hour.

Natsume asked, "Since you have this, do we still need to follow them?"

Nova nodded. "Yes, because if this man has bad intentions, Ikuse Tobio's life will be in danger, and I won't be able to protect him from here."

"I see," Natsume nodded in understanding.

"Well then, let's go," said Nova. After passing the coordinates of his, Natsume's, Tobio's, and the Caucasian Man's position to Lavinia and explaining the situation, Nova and Natsume made their way to the shopping complex.