A Terrified Teacher at Ghoul School!, Vol. 16

Now that Haruaki's clumsiness has accidentally awakened the god of Hyakki Academy Island, it's up to him to figure out how to stop it from eating everything in the Pacific Ocean! And that's not the only supernatural disaster he'll have on his hands. While he, Hatanaka-sensei, and Nyuudou help Tamao get ready for his Spookology makeup exam, Tamao's divine youkai magic suddenly goes out of control, transporting them…back in time?! Will they manage to escape the past without changing their future…?

Volume 16 of A Terrified Teacher at Ghoul School! manga series by Mai Tanaka.