Kaisei no Caricature

Kaisei no Caricature (廻生のカリカチュア, lit. "A Caricature of Reincarnation") is a manga series by Hiromu Mogi and Sakurako Gakurakuin with illustrations by Sora Gouto. It was serialized in Shōnen Gangan.

Plot
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 un-enterable 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!