Toilet-bound Hanako-kun manga volume 3 features story and art by AidaIro.

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 4:00 P.M. 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!