Yamada, who works as an ordinary company employee, goes to visit the family home left behind as an inheritance by his late grandfather, and there he finds a door to another world!!

Beyond the door, he meets a talking black cat and a homunculus girl, and as he begins living together with them, he enjoys a cheat magic life in modern Japan and a heartwarming slow life in another world♪

The best-of-both-worlds life of 35-year-old bachelor Yamada, between another world and reality, begins!