This world has been invaded by bugs.With the appearance of the ``Armor Bug'', a mutant insect monster that can defeat all modern weapons, humanity has been robbed of much of its range of survival.The only ones who can stand against such armored insects are the ``Chouhi'', girls who harbor ``insects'' that have evolved differently from armored insects.One of the candidates to become a butterfly princess, Ayumi Komiwa, is still suffering from the reality that she cannot become a butterfly princess.Her best friend, who was supposed to be with her, has left her, and the person she admires no longer treats her in the slightest.Those days of despair came to an end when he was on the verge of death in a battle with armored insects.``Why don't you just die for nothing!''With the end near, the girl transformed her body into a butterfly. And the flapping of its wings transforms the world ...