Jin: Kakuto Haouden

In the near future, society has sunk into corruption, stripped of all hopes and dreams. In this world, the illegal, no-rules underground fighting event "Yaoyorozu" has reached the peak of its popularity.
Brutal street fights break out anywhere and everywhere, driven by money and desires. Matsuriya Jin, a delinquent boy who has been surviving by stealing on the streets, gets caught up in this violence. But his potential as a fighter is overwhelming...
A hard-hitting battle action series begins as an abnormal monster smashes everything in his path.

(Source: Kodansha, translated)