It’s summer vacation time, and no one is more excited about it than 2nd year high school student Karin-chan. Her childhood friend Sakumi-senpai is coming home from college to visit! Karin and Sakumi, along with his younger brother Tatsumi are childhood friends. Sakumi hasn’t been gone long, but now that he is back, Karin can really see a difference in him. Just seeing him makes Karin’s heart beats faster. Her crush on him hasn’t changed.
Meanwhile, Tatsumi is the same age as Karin, and is in her class at school. He is aware of Karin’s obvious affection for Sakumi, however what are his feelings? He seems to care for Karin very much, could he be the one to comfort Karin when Sakumi rejects her? Over the summer, Sakumi begins to see how special Karin is. Will Karin gather the courage to confess? Will Tatsumi make his feelings known? Will Sakumi realize how special Karin has always been to him?