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 was when he was alive, but that doesn't mean he can't help him solve his unfinished business! Will the junior exorcist be able to help this friendly ghost pass on...?
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 everyone who's ever attended Kamome Academy--past, present, AND future! But whatever you do, don't read the red books...or your future will be drenched in blood!