Preying on the dreams of human beings, but also giving its host supernatural powers are the Mushi, which have appeared for a decade. Kusuriya Daisuke, while on the train to school, comes across a girl named Shiika and that meeting sparked an attraction between the two. However, Shiika was a MushiTsuki who had escaped from the country's top secret facility. Due to that reason, the Special Environmental Prevention Bureau had dispatched their top and strongest agent, the MushiTsuki known as "Kakkou" on a mission to mercilessly eliminate Shiika.

The people who are harboring dreams, and the painful but strong wishes in them, are about to enjoy the coming Christmas.

This is the Encounter of a Boy and his meeting with a Girl.

The Most Beautiful yet Disastrous story of this Fateful Encounter