As Winter settles in, Tooru finds an abandoned kitten and decides to take care of it. After showing the cat to the others, Tooru goes with Run to visit a pet shop and a family restaurant, where Run comes with a name for the cat, Tansan. The next day, snow falls at school and the students have fun playing in the snow, except for Nagi who is noticeably bothered by the cold. By the next day, however, everyone but Nagi catches colds.
とあるの冬の日。るん、ナギ、ユー子は3人でトオルの家へ遊びに行くことに。
いつもは整頓されている部屋が珍しく散らかっており、不思議に思っていると、現れたトオルの腕には、一匹の子猫が抱えられているのだった。
어느 겨울날, 룬, 나기, 유코 3명은 토오루의 집에 놀러 가게 된다. 그런데 언제나 정돈되어 있었던 토오루의 방이 엉망진창으로 어지럽혀 있는 상태. 그것에 의문을 느끼고 있는 일행앞에, 토오루는 한마리의 아기고양이를 안고 들어 왔는데...
