It's a showdown for the ages as the legendary hero takes on the corpse god necromancer, but when the dust settles, something isn't quite right... In the final moments of their epic confrontation, the corpse god's final gambit shot was wholly unexpected -- reincarnation magic! Across space and time, a boy named Polka Shinoyama awakens feeling...not quite himself...... Who could've expected that the climactic battle between good and evil would turn out like this??

As a result of an accident in the real world, Asahi Ikusaba is transported to another world. He tries to enjoy the different world he imagined, but his abilities prove to be the weakest. Just as he's about to be attacked by a vicious monster, Asahi's doting elder sister Maya comes into his rescue and saves him. Chasing after Asahi's love, Maya too ended up in the same world as him, with the strongest of abilities and cheat skills. The fantasy tale of the strongest elder sister with a brother complex and the younger brother with the weakest skills begins.

A boy who's been brutally bullied all his life discovers a door to another world, which grants him access to cheat skills and opportunities to live a better life.