Manga: Toilet-bound Hanako-kun, Vol. 5
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...