Maou No Kyoushitsu
Other titles :
魔王の教室, Maoh no Kyoushitsu, The Demon's Classroom
Author(s) :Yoshikawa Miki
An oneshot by Yoshikawa Miki; a teacher for the fifth graders claims to be the king of the underworld!? Some of the students then decides to investigate him, is he really from hell?