One day, all the eighth grade students were transferred to another world. The princess of the other world summoned them to make up for their lack of strength. The students are threatened and decide to follow the princess, and they are made to take a magical power test to determine their abilities. While everyone is sorted according to their results, Kokubun Kento's result is a flop. Judged as useless, he is expelled. However, there is actually a tremendous ability lurking within Kento...

Become a cat and enter another world. An adventure that's not just cute begins! A boy reincarnated in a different world aspires to be an adventurer, but his body is that of the weakest race of cat people, and the magic he wields is an empty attribute that is ridiculed as "empty". However, the boy ignores the big handicap and uses his ingenuity to create weapons and armor from sky magic, transforming it into magic that allows him to walk in the sky. When he grows up supported by the kindness of those around him, and when he realizes the true value of the sky attribute, his journey as the strongest catman adventurer begins!