Rudo lives in the slums of a wealthy town with his foster father Legto. Despite their different social classes, they try to coexist peacefully with the other residents. However, Rudo is contemptuous of the wastefulness of the upper class and often rummages through the towns garbage in search of valuable items to save from being discarded into the "Abyss," a massive hole where anything deemed trash is dumped, including people. His biological father was also thrown into the Abyss after being accused of murder.
One day, while on his way home, Rudo encounters a mysterious figure and returns to find Legto's dying body on the floor. The authorities charge him with murder, but no one believes his claims of innocence. He is subsequently thrown into the Abyss. Instead of perishing, he finds himself in an unfamiliar, foul-smelling location surrounded by monstrous creatures made from trash.
When Rudo is attacked by these monsters, he is rescued by Engine, a "janitor" who wields special weapons called "jinkis" to combat the garbage beasts. In order to avenge Legto's death and escape the Abyss, Rudo reluctantly agrees to become a janitor himself and fight his way back up and out of the hole.
Gachiakuta has been published digitally as an English simulpub through K Manga. The volumes have been published by Kodansha USA since January 16, 2024.