Gachiakuta

Rudo lives in the slums beneath a wealthy city that discards objects and people with equal ease, spending his days rescuing useful things from the trash. When his adoptive father Regto is murdered, Rudo is framed for the crime and thrown into the Pit, the punishment reserved for those the city decides are worthless.

Instead of death, he finds a toxic wasteland where enormous beasts are born from accumulated garbage. Enjin, one of the Cleaners who fight with weapons empowered by treasured objects, saves him. After awakening a Vital Instrument of his own, Rudo joins them in search of a way back to the surface and the person who destroyed his life.