"Hanako-san, Hanako-san...are you there?"

At Kamome Academy, rumours abound about the school's Seven Mysteries, one of which is Hanako-san. Said to occupy the third stall of the third floor girls' bathroom in the old school building, Hanako-san grants any wish when summoned. Nene Yashiro, an occult-loving high school girl who dreams of romance, ventures into this haunted bathroom...but the Hanako-san she meets there is nothing like she imagined! Kamome Academy's Hanako-san...is a boy!

Nene Yashiro serves as the assistant to the School Mystery Hanako-kun. When she is invited by enigmatic playboy Natsuhiko to a mysterious tea party, she meets Hanako-kun's "girlfriend" and his "little brother"...!? On top of that, she learns that one of the Seven Mysteries is mixed in with her classmates...