The story is about a girl called Minyoung who accidentally bumps into a boy in the hallway of the school. That boy's name is Lee Sungyeol. After that scene they start to spend more time together and little by little they fall in love with each others. Everything is fine between Minyoung and Sungyeol until one guy called Jaehyo appears in Minyoung's life and he messes up everything. And the love triangle begins!