Koiko Natsume has always aimed for mediocrity in all aspects of her life. Her appearance is average, her grades fall in the middle of the pack, and she makes few impressions on those she interacts with. Her boyfriend also fits the bill for her "normal" lifestyle, as they share ordinary kisses. Koiko truly believes that this is what it means to be happy.
Understandably, Tsurugi Ninomiya seems like an unlikely friend for Koiko. Good-looking, athletic, and intelligent, he is everything that goes against her personal beliefs. However, after Tsurugi reveals that Koiko's boyfriend has been unfaithful and points out that Koiko has never looked truly happy around him, her average world is thrown into chaos. Can an ordinary girl like Koiko find true happiness amidst the chaos?
