Tsukki is cold. A young elementary school girl who's distant and seemingly rather apathetic. When rather abruptly her life would start to change, as she meets Kiragi. Kiragi is everything Tsukki isn't, he's popular, nice, amiable, and warm. However the one trait they seem to share in common is being disingenuous. So with some prodding from Kiragi, the two try to start and open up to each other. However, simultaneously, they quickly become witnesses to murders in the snow. They realize that they'll have to work to solve this as quickly as possible, or else Tsukki very easily could be the next on the chopping block. While dealing with their emotions, personalities, and the serial killer dubbed 'the frost demon', the two find themselves perhaps falling in love.