Aidairo: 9 books

Through the workings of the School Mystery Clock Keepers, Kamome Academy's entire student body is covered in wrinkles!? To restore peace to the school, Hanako-kun teams up with a certain someone. Just when they thought the case was headed to its conclusion, the secret of Hanako-kun's assistant Nene is brought to light! What could it possibly be!?

Hanako-kun's assistant Nene has suddenly been dragged inside a mirror. Through the looking glass, she meets the spirit of a young boy calling himself Mitsuba. They try to escape the mirrors together, but the threat of No. 3 of the Seven Mysteries, the Hell of Mirrors, draws nearer. Who is it that saves them just in the nick of time...!?

It's been three days since they returned from the School Mystery Three, the Hell of Mirrors. To cheer up the depressed Kou, Nene heads to the Boundaries' Tanabata festival. She was supposed to be enjoying the festival with Hanako-kun and Kou, but suddenly she finds herself in the world 50 years in the past. And who should she meet there but Hanako-kun when he was alive!?

That day, Nene went to school as usual, but found Hanako-kun acting like one of her normal classmates...!? She seems to be the only one who notices anything amiss, seeing as Hanako-kun was supposed to be a ghost...! Hunting for the truth, she heads to a mysterious tower. Fact and fiction clash in this Seven School Mysteries ghost story!

"Hanako-san, Hanako-san...are you there?" At Kamome Academy, rumors 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,...

Nene Yashiro has made a pact with "Hanako-san of the Toilet" aka Hanako-kun to hold off the curse that has been placed on her. To rescue her friend from the clutches of one of the school's infamous Seven Mysteries, she and Hanako-kun infiltrate the Misaki Stairs. Presenting the second volume of the retro horror romantic comedy--about an occult girl and an inhuman supernatural boy!

Nene and Kou want to learn more about their mysterious friend, Hanako-kun--and what better way to do that than school mystery number five, The 4pm Bookstacks! The rumors say that a secret door in the library leads the way to a supernaturally special collection. The Bookstacks know everything about...

Nene steps into the spotlight! The mermaid kingdom hasn't forgotten her, and they're back to claim what's theirs! Can Hanako protect her from becoming permanently fishy? Meanwhile, Kou makes friends with an odd ghost haunting the entrance to the middle school division. Kou has no idea who this guy...

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...