Sakazaki Sōsuke, who died in a traffic accident, was originally meant to be reincarnated into an ordinary family in a world separate from his own. However, due to divine circumstances, he was sent to the lower levels of a dungeon in another world.

Of course, the Reincarnation God responsible for Sōsuke's transmigration provided all the assistance they possibly could.

Upon receiving this aid, Sōsuke was then transferred to the dungeon's lower levels. From there, this is a story of him adventuring through the dungeon for the time being, aiming for the surface.