アンダーグラウンドベイビーズ

Underground Babys

Tenma, a yakuza, is in charge of running an underground arena where once you fall in, you never get out alive. He spends his days in this routine, until a mysterious young man named Tatsu appears before him. Tenma takes an interest in Tatsu, but...?! (Source: Akita Shoten, translated) Note: Includes one extra chapter.