Mark teaches first grade, and part way through the first semester he gets a new student. He is immediately taken by his insanely attractive father. His coworkers Jeno and Jaemin want him to go for it when he is a little apprehensive at first. It doesn't take long for him to figure out that he likes him enough to give it a try. Renjun is a single father who works as a graphic designer. He drops his son off everyday per his request and is instantly attracted to his teacher.