Fandom Wiki! I only date Tsuchigomori for this one. Basic info on the series below.

Jibaku Shounen Hanako-kun (地縛少年花子くん Jibaku Shōnen Hanako-kun or Toilet Bound Hanako-kun (TBHK) was a short 12 ep show. As of right now there are 21 books.

Synopsis from the website (unofficial translation):Hey, do you know about the Seven Mysteries in this school……? Rumours abound at Kamome Academy, about the most famous of the Seven Mysteries. It's said that Hanako-san is in the third stall of the third-floor girls' bathroom in the old school building, and will grant any wish of the person who summons them. The method of summoning is simple: knock 3 times. And then–––"Hanako-san, Hanako-san... are you there?" "Y–e–s……" To have her wish granted, occult girl Yashiro Nene has summoned Hanako-san. But the ghost that appeared before her is a boy in the girls bathroom. "Hanako-kun". Nene gets involved in all sorts of supernatural stories by Hanako-kun, who's sadistic and slightly-- perverted despite being a ghost. Will Nene ever be able to lead a peaceful school life again? A heartwarming comedy that no one has ever seen before begins now...