High school student Yamako moves to a small island in Kyushu, Japan. There she meets and falls for senior student Minami, but she can't reveal her feelings for him. Whenever she passes by him at school her heart starts to flutter and her emotions for him gets stronger. One day, while writing a love letter to Minami that she will keep for herself, high school student Fuwa catches Yamako writing her letter. Afterwards, Fuwa helps Yamako to gain Minami's attention, but Yamako has a secret nobody knows about...