A couple that has been together for 3 years, but dated even less than 100 days… And, because of the playing-hard-to-get Jaehwa, Dohyung is making a fuss. Dohyung wants to do something about it, but because of the naive Jaehwa, he gets really upset. However, the highschooler who lives on the 1st floor is weird. Their story is all about being foolish and clumsy in front of love.