Hirono Hiro is a high school student, and secretly a shoujo mangaka, to all but his childhood friend and kouhai, Kei Shindo.

One cold Christmas after meeting a mysterious woman in church, a strange girl steals his bike.
Running after her, he finds her collapsed on the street.

Learning her name is Miyamura Miyako and that her bag was stolen by a man on a motorbike, Hirono finds himself spending time with Miyako, much to the dismay of Kei...