The story takes place between the first and second seasons, where Rimuru confronts the swirling conspiracies in the Coleus kingdom.

Believing he's the last Ogre survivor of the Orc massacres, Hiiro enters the service of Queen Towa of Raja and tries to lift a curse with Rimuru's help.

Defeating numerous villains in the abandoned area in Z-City but still having problems with rent money (and continued harassment from the landlady who says he's 3 months overdue), Saitama speaks with a shop owner who is being forced by a local gang to surrender his store's deed. Several other shops have gone out of business and his store is the last one; a conversation between the gang boss and one of his stooges reveal that the boss has had an impulse to buy out all the stores in the area to destroy them.