Mayonaka no Ariadne
真夜中のアリアドネ
Worries are about your height, whether or not you will do alright in a new class. For a normal high school student, Chiyoko's days were about such worries. But from the day she met her childhood friend Chiharu again, Chiyoko's world changed in a big way. When Chiyoko stumbled into a underground secret club beneath the surface she would discover a surprising truth....
(Source: StarryHeaven)