A story about a first-year high schooler named Mio. Although she always yearned for a perfect, sparkling life, she felt that it wasn’t in her affinity. Her younger twin brother Yuta, on the other hand, is a social butterfly who makes people around him laugh easily. However, one day, Mio's life is changed in a big way due to an encounter with Rin, an upperclassman who is one year older.