The main character, Kaidou Maruo was hungry.

He broke pretty much everything, like punching bags and a mitt at the boxing gym, pillars at the sumo stable, and large baking equipment at the bakery...... whatever he touched, he destroyed.

Yes! Maruo was hungry for battles.

Maruo wanted to be like the anime heroes. He wanted to battle like the characters in Dragon Ball, JoJo's Bizarre Adventure、Kinnikuman, and so on. He wanted to be strong, and to train hard enough to become a hero of the world. By the time he was 7, he could smash a boulder with his bare fist.

However, due to his hard training, since he was very young, he now cannot control his strong power well at work. So he could not get a job, and even if he could he would get fired very quickly.

One day, a bunch of louts were following a beautiful girl, trying to catch her.

Maruo attacked them right away to save the girl. He even gave her a piggyback ride to run away to the back alley.

She laughed and introduced herself as Urara. She also asked Maruo to “exchange a cup.”

The custom of “exchanging a cup” in the Japanese yakuza world means that to make a pledge of brotherhood. After exchanging a cup, the two parties become a boss and a subordinate.

Yes! Unexpectedly, Urara was a leader of Yakuza family!!

Maruo was hoping to live normal life as an ordinary person, so he was depressed. He thought his talent was only good for yakuza people.

Surprised Urara told Maruo,

Maruo was in shock by Urara's words.

Then the mysterious bad guys who were following Urara showed up again with their true appearance, as monsters. They started attacking the two again.

The yakuza guys who control the Japanese underworld were all Ayashimon. They usually pretend to be normal humans. Maruo was attacked by the super strong ayakashi and then he flew away!

But he was smiling and happy!

He could finally battle as he wished!! He was starving for battles with strong opponents.

Maruo counterattacked guys from Enma-kai and won. Then, he agreed to exchange a cup with Urara. Because he realized that this was the only world he could live in.

Urara and Maruo lick each other’s blood - “the exchanging of a cup” is done.

Shinjuku Kabukichou was the town that all the Ayakashi in Japan gathered.

The mysterious yakuza leader/Ayashimon who wanted to be on the top in this town and normal person, Maruo, will start the beautiful but unexpected yakuza story!!!