Martial Arts System - Chapter 60: Dirty Mouth Ichiro.

A former sporting rifle shooter genius transforms into the ‘Juvenile Butcher’. While originally supposed to have received the death penalty, he was instead fortunate enough to have entered a secret and highly regarded armed force, throwing himself into the ‘Nirvana Project’.

Yakuza, originally refers to the most stinky card in the Japanese flower letter, whoever gets it will inevitably curse.

A young director traveled to Japan in the 1980s, and he inexplicably became a Yakuza named Takeshi Iwata.

As a result, a wonderful journey of Japanese movies started like this.

- Description from novelbuddy

An F-Class Hunter.

A little ruffian who fought recklessly without any morals and bottomline accidentally time-traveled to parallel space and became a Key Case Investigation Team agent. The huge change in identity had him creating chaos in the police station. However, a strange miracle system helped him repeatedly solve mysterious cases, turning him into an impudent ruffian detective!