Kondo Kotaro, who abruptly dropped dead, was transferred to another world.

Heroes and Demon Lords have been gone for ages, and humans and monsters have finally started building a town in the frontier to coexist. Kotaro, a rare visitor from another world, is also dumped into this frontier town.

The story follows him as he meets a monster named Arachne at the Adventurers' Guild and, while living as a kept man, begins a business.