Toilet-Bound Hanako-Kun Vol. 3 (manga)

"I'm not going anywhere."
Nene and Kou want to learn more about their mysterious friend, Hanako-kun-and what better way to do that than by hunting down school mystery number five, "The Four P.M. Bookstacks"?! Rumors say a secret door in the library leads the way to a supernaturally special collection. The Bookstacks know everything about everyone who's 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!