Lateral

is a Japanese light novel series written by Otsuya Shihoji, with illustrations by Okada Amitsu. The series began publication on February 10, 2015 by ASCII Media Works under their Dengeki Bunko publishing imprint.

Synopsis
Hatonosu theory, a boy whose purpose is to solve the mystery.

On the first day of the first semester of the second year of high school, it was a strange schoolgirl who was all white in the back of the discussion in the new class. Recommended by Mizuhira. A mysterious girl who hides her skin to the limit and introduces herself with synthetic voice. The moment the theory touched the skin in the wake of an accident, the world suddenly went dark.

The theory drawn into the dark space dominated by "Angel" challenges the [Understanding] of the mysterious [Situation] created by "Angel" in order to unravel the mystery of that space and its recommendations-"Horizontal Thinking Reasoning Game" ], [Starting the situation]!