挑戦者は戦い合い、殺し合う、「最強」を決める六道トーナメント。

チャンピオンは、富、名声、力、この世の全てを手に入れ、まさに世界の王様になる。

この世の金と熱狂の全てが集まる、世界唯一にして最高の娯楽だ。

――そんな世界を支配する弱肉強食バトルに、ゴミ拾いをして生きのびる貧しい少年・縁が、「最底辺」から「最強」を賭けて挑む！

In a world where humanity escaped underground to survive, En is an impoverished boy who lives off the trash of those more privileged than him. He spends his days in the slums, looking through a trash heap for the decomposing bodies of “losers,” those who were defeated and killed in the “Battle of the Six Realms.” To participate combatants have to undergo an expensive “body modification surgery,” and En sells these modifications, machines attached to their bodies that significantly increase fighting ability. Uninterested in the tournament and its champion, unlike everyone else, he aims only for a worry-free life. But one day, a chance encounter with a mysterious man shatters his reality and puts him on a different, more gruesome path.