Volume 5

The 5th volume of the manga. It covers Chapters 21 to 25.

Synopsis
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...

The Three Clock Keepers Part 1
Aoi Akane recounts to Yashiro Nene the First School Mystery, which is about the Three Clock Keepers who guard a magical clock present in the school that controlled the flow of time throughout it. If anyone touched the clock without the Clock Keepers' permission they would steal the time remaining in that person's life.

Yashiro is terrified at this rumor and thinks to herself how she had at first found Aoi's rumors to be fun but ever since she had met Hanako all the rumors Aoi told her came true. Yashiro wonders if this is the next rumor she will have to investigate and is jogged out of her reverie as Aoi comes close and tries to tell her something.

She is interrupted however by yelling coming from their classroom. As they rush to their classroom, both of them are shocked to find it in a mess with all the plants in the room overgrown, the desks rusted, the floor caked with a thick layer of dust and all the windows broken. The students find that all their belongings present in the classroom prior to the incident had also been ruined, however Aoi sees that her belongings were unchanged. Yashiro thinks over this turn of events and upon seeing the sudden growth spurt of the plant in the classroom and thinks that it was as if time had jumped forward for everything in the room.

When she tells this story to Hanako, he is intrigued but before he can say much he is interrupted by Minamoto Kou suddenly appearing and loudly asking Hanako for his help. He says that two boys from his classroom had suddenly turned into old men not long after the incident at Yashiro's classroom. Hanako confirms that these are the doings of a supernatural and that it could only be one of the Seven School Mysteries. Yashiro interjects and says that she had heard of the First School Mystery from Aoi just earlier that day and Hanako is glad she has already heard the rumor so that he doesn't have to tell it himself.

Hanako explains that the Three Clock Keepers each have their own power of control over time. The First Keeper can turn back time, the Second can stop time and the Third can move time forward. Seeing that it could only be the Third Keeper causing such mischief throughout the school, the trio team up and go to find the Third Keeper.

As they make their way to find the supernatural, Kou asks Hanako if he knows where the Keeper would be and Hanako replies that he does not know. Kou is irritated and asks how the Leader of the Mysteries would not know where they are. Hanako responds that the Keepers were prudish and that the first time he met them they told him never to see them again after they were disgusted at him when he said they could do all the perverted things they wanted with the use of their powers. Consequently he was not even aware of where their boundary lie and Kou gets into an argument with Hanako about his perversion, leaving Yashiro disgusted.

Seeing that Hanako was no better off than they were at knowing the whereabouts of the Keepers, Yashiro sighs but suddenly Hanako remembers that the Second Keeper was hiding as one of the students at the school. He says that he already has a good idea of who they are looking for and leads the trio to Yashiro's classroom, saying he sensed a supernatural presence from it. He reveals to Yashiro his suspicion of Aoi, pointing out that her belongings had been unaffected by the Keeper's power. As Yashiro thinks over the matter, the door suddenly bursts open with Aoi and Akane Aoi behind it and Aoi rushes forward to greet Yashiro.

Seizing this opportunity, Hanako quickly posseses Yashiro's body, much to her shock. He grabs Aoi's arm and pulls her down, asking her with a sneer if she were hiding anything from Yashiro. The others look on in shock at this turn of events and Yashiro herself observes the goings-on as an apparition from the ceiling.

Features

 * This volume includes an extra 4-koma one-shot by AidaIro that they drew for GFantasy's manga contest, About 8 Manga Battle. The one-shot features Akane, Lemon, and Aoi.
 * This volume includes a preview of volume 6.