Mogi Hiromu

Student of Private Academy Clanmine, Shirogane Mitsuki, repetitively experiences a dream wherein an elder brother he doesn't have dies protecting him. An Absolute Hierarchy System that is determined by the uniform, an elder brother who shouldn't exist, and an unenterable clock tower that nobody has ever set foot in… When the hidden truth behind this warped school is brought to light, a fateful adventure awaits!

It is rumored that if you get lost, you will never be able to return to the "Lost Fourth Floor". Who is waiting on that "Lost Fourth Floor"!? ? Hanako and Kinjiro, who are familiar with "Gakko no Kaidan", are very active against evil spirits and youkai! ! The long-awaited comic version of the new sense of youkai action story!