Geonwoo and Haru have been friends since elementary school. Now university students, their friendship continues as strong as ever. Both are currently single so after her friend cancels their Christmas Eve plans, Haru decides to invite Geonwoo to spend it with her. A memory of a promise made when they were younger as well as Haru’s choice in clothing that night makes Geonwoo start seeing Haru in a different light, and the fine line between lovers and friends starts getting blurred.