In a world where mysterious phenomena of humans suddenly turning giant and going on a rampage began to be observed everywhere. Amidst the chaos, magical girls appeared to fight the giants and gave people hope. One day, a boy named Gendai Hiraga, who was being attacked by a monster, encountered a magical girl. At that moment, as she fought with her back to him, Gendai was captivated by her buttocks. Five years later, Gendai has grown into an invention-loving boy who adores chemistry. Because of his overwhelming love for magical girls, he became a "crossdresser" (otoko no musume) and fought as a "magical girl" using the power of science. He is still searching for that magical girl who saved him... This is the story of Gendai's battle as he searches for the magical girl with the enchanting buttocks.