Chapter Text
Yokohama has always been a peculiar city. The security surrounding its borders was stringent, allowing very few people in. Tourists were rare, permitted entry only once or twice a year. Then came the dawn of quirks—when children began manifesting supernatural powers. In response, the city's security measures only intensified. Massive walls were erected around the perimeter, along with a transparent, dome-shaped shield to prevent aircraft from entering. It seemed as though Yokohama was hiding something from the world, but no one knew what.
The city had remained silent ever since, making no contact with the outside world. The scant information available suggested that the entire city was quirkless. Not a single person possessed a quirk, which, beyond Yokohama's walls, was considered essential for survival. Without a quirk, society would turn its back on you.
Another piece of shocking information for outsiders was that Yokohama had no heroes. In a world filled with life-saving heroes flaunting their powers and flashy costumes, constantly in the public eye, the absence of any heroes in Yokohama felt... wrong. A society without heroes to combat villains? It simply didn’t make sense.
This fueled wild rumors. Some claimed Yokohama was secretly developing a bomb capable of wiping out the outside world in seconds. Others believed the city harbored alien creatures to aid in world domination. But the most persistent rumor was that the city was controlled by villains. After all, without heroes, wouldn’t it make the perfect breeding ground for them?
The last, and perhaps most secretive piece of information, was known only to the government. Twenty years ago, in an act of desperation, heroes, including the top five, were sent to breach Yokohama's borders. The government had grown tired of the city’s veil of secrecy. However, the mission was a disaster. Every hero, including the number one hero, All Might, returned grievously injured, some barely alive. At the border, they were met by a group of people dressed in elegant suits. These individuals—though appearing quirkless—warned the heroes to leave and never return. The heroes, undeterred, attacked, intending to make a point. But what they encountered was far beyond their expectations. These mysterious people didn’t fight with quirks; their abilities were far more powerful, almost otherworldly. Surrounded by strange kanji and symbols, the heroes were swiftly defeated, most left unconscious or too wounded to continue. The ability users sent them back beyond the border with a final warning: if they returned, they would be killed.
Since that fateful day, no hero dared approach Yokohama, and the city fell back into obscurity. Until 20 years later.
It was a cold morning in Musutafu. The sun glinted off the fresh snow covering the streets, as people happily bustled about. Children played in the snow, couples strolled on romantic dates—everyone seemed to be enjoying a wonderful day. Well, almost everyone.
Mori Ougai, the Port Mafia boss, was having the worst day of his life. The last thing he wanted was to owe a favor to a rat (or bear, depending on how you looked at it). Yet here he was, sitting in Principal Nezu’s office, asking for help. Back in Yokohama, a terrorist group—ironically also composed of "rats"—was wreaking havoc. This "little" group had proven to be a far greater threat than Mori had anticipated. Even with the combined efforts of his executives and the Armed Detective Agency, they couldn’t handle them. Left with no other option, he was forced to seek help from the outside.
"You know, Mori-sensei," Nezu mused, "you’re the last person I expected to come asking for help. This must be quite the situation to bring in ‘outsiders.’"
"I’m afraid so," Mori sighed. "So, will you be a good neighbor and lend us a hand?"
"This situation could certainly bring unwanted attention to the heroes, especially from the so-called ‘Decay of Angels.’ However, I would be happy to assist—on one condition."
Mori's heart sank. This rat was cunning, and it didn’t take a genius to see an opportunity to use this situation to his advantage. Whatever Nezu wanted, Mori hoped it wouldn’t involve exposing Yokohama.
"And what, pray tell, is this ‘one condition?’" Mori asked warily.
Nezu’s eyes gleamed. "After we defeat the terrorist group, I want your two young executives to attend UA as heroes-in-training."
Mori blinked. What? This was the perfect opportunity to uncover Yokohama’s secrets, but Nezu wanted his two youngest executives to... go to school? He turned to his subordinates. The shorter ginger-haired boy looked utterly baffled, his blue eyes wide with confusion. He stared at Nezu as if the principal had suddenly grown a second head. Meanwhile, the taller boy standing beside him—thin, dark-haired, and wrapped in bandages—remained expressionless. His uncovered eye was unreadable as he glared at the principal, though it was impossible to tell if he was surprised at all. After a moment, the taller boy turned to Mori with a smile, as though he hadn’t just been glaring daggers at Nezu.
"I think it’s a wonderful idea! What do you say, chibi?" he asked, glancing at his partner.
"First of all, how many times have I told you not to call me that? And second... I don’t know," the ginger-haired boy murmured, his thoughts clearly elsewhere.
For Mori, the decision was obvious. Even if his shorter executive hadn’t realized it yet, the boss had, and he suspected the taller one did too.
"Very well, Principal. I accept your condition," Mori replied. With that, the rat-bear principal and the Mafia boss shook hands (or paws), sealing the deal.
This was too perfect.
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