"Your sister has very little time left..." says the girl who appears in Shogo Tokisaka's dream.

Your sister is doomed to die, and there is no time left. So, if you want to help her, you must make a contract with yourself, take someone else's time, and share it with them. This is the destiny that has befallen the boy.

A wish fulfillment, a deal with the devil. A clockwork beast stops time in the city at night and attacks people in the stopped time. People who disappear. Memories that disappear. When a loved one disappears, the boy's choice is - and the devil smiles.

Her name is Mephistopheles.

CocytusGarden presents a series of dark and bizarre ADV, Clockwork Mephistopheles. The first story describes the encounter between a boy and a demon and the beginning of their battle.