In order to satisfy his sexual desires, the protagonist attempted to summon a succubus. When he began the ritual, he and his childhood friend ended up in a large communal bath at a succubus academy in another world! In Farench Deshka Girls' Academy, the succubus have boobs that have grown to the brim with milk and perfect bodily proportions. Our protagonist was summoned to this world by the director of the school who held a summon gacha on her own to save the school. The "erotic deviation score" of the school is too low. Therefore the government of Lilingard, the country of succubus in the world of Yggdrasil, is closing the school in one year. In order to save the school, the succubi must become more lewd and raise the erotic deviation score. To ease his dismay, the director grants him the succubus skill "Sex Scouter" which unlocks a vast amount of "Erotic Skills" that makes him surpass majin-level.
With the school's fate on the line, our protagonist has no choice but to become the legendary hero. And with the help of his erotic magic book that he received without permission, he will be able to save the succubus school. With this spellbook and new skills, it is now possible to conquer this school and become invincible in this world. It's time to rebuild the succubus school and build a succubus harem!