The protagonist, who loves boobs and bunny girls, is the head of the App Development Club. It has been secretly and casually developing a bishoujo game—an adult game—titled "Welcome to Impregnation Isekai Oppai Bunny Academy! (Tentative Title)" under the guise of a legitimate club activity. (Officially, the club pretends to be a wholesome extracurricular group, but in reality, it is nothing more than a "Bishoujo Game Development Club".) However, on Usaki Academy's parents' day event, while debugging the game, the protagonist is suddenly transported into the alternate world of the very erotic game he had been developing! The world he was transported to was Yggdrasil, the world setting of the bishoujo game the club was developing. Every student, teacher, and even the school director had spectacularly huge breasts—and on top of that, they were all ! It was truly a bunny girl academy so stimulating that it made his lower half feel like hopping with excitement! It was later revealed that his transportation to this world was actually a summoning performed by the academy. The protagonist was hailed as the , tasked with saving the school, which was on the verge of shutting down due to a decline in its low bunny deviation score. As the academy's director performed a skill search on him, at that moment—his 'Ultra-Lewd Education Skill' activated!
