Shinjuku's Quarantine Zone, one of Tokyo's most dangerous neighbourhoods, was eerie even during the day. Its narrow streets, graffiti-filled walls and abandoned buildings were like a scene of crime and chaos. But in the midst of this chaos, there was order: gangs. Each neighbourhood had its own flag, its own leader and its own rules. The only way to survive in this world was to join a powerful gang or challenge everyone.

Kaito Yūzora chose the latter. 18-year-old Kaito was looking for more than just fighting. Years ago, his older brother Haruto Yūzora was the leader of one of Tokyo's most powerful gangs, the Shadow of the Wind. But Haruto's mysterious disappearance caused the gang to disband, leaving Kaito at the mercy of the streets. Now, while Kaito was on his brother's trail, he was also making a name for himself in street fights.

On this day, Kaito was called to fight in an abandoned park in the territory of a gang called the Black Circle. The Black Circle was one of Tokyo's most aggressive gangs, and their leader, Renji Kisaragi, was ruthless in combat.

As Kaito stood in the centre of the square, Renji and his men surrounded him noisily. Renji advanced towards Kaito, tall, wearing a black leather jacket and an arrogant expression on his face.

> 'Yūzora, a boy like you won't last long on these streets,' Renji said sarcastically.

Kaito looked at Renji without taking his hands out of his pockets.

> 'If you can shut me up, I'm here to try.'

The crowd gathered to watch the fight. Renji's first punch came towards Kaito, but Kaito quickly stepped to the side and countered with a hard knee strike that staggered Renji. Renji's men began shouting, but the expressions on the faces of everyone who had looked down on Kaito quickly changed.

Kaito had developed his fighting ability as a survival skill. His speed, strategic thinking, and keen ability to spot his opponents' weaknesses made him unique. But this fight was not just a street brawl. It was a message.

When Renji fell to the ground, he was furious.

> 'Do you think someone like you will rule here?' he shouted.

Kaito lowered his head and replied coldly:

> 'I'm not here to rule. I'm just here to finish the unfinished business left by my brother.'

A look of surprise appeared on Renji's face.

> 'Don't tell me you're Haruto Yūzora's brother...'

These words made Kaito nervous. He was facing someone who knew something about his brother. But this was no time to talk; Kaito chose to answer Renji with a fight.

Soon the fight was over. Renji lay on the ground, defeated. The crowd was silent, but the silence signalled the rise of Kaito as a new force on the streets of Tokyo.

But Kaito was in no mood to celebrate his own victory. When the fight was over, a man next to Renji approached him and spoke in a low voice:

> "If you're looking for Haruto Yūzora, be prepared for real war. He is still alive... but things are more complicated than you think."

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