Every day, a young girl wearing a mask stands by the beach and sings a nostalgic melody. After experiencing two sudden heart-wrenching partings when she was only a child, Nino Arisugawa has been singing her songs to the ocean, bound by a promise made with her two childhood friends—her first love, Momo Sakaki, and a boy who composed music, Kanade "Yuzu" Yuzuriha. Having never met each other, the boys both individually promised that if Nino was ever separated from them, her voice would be the beacon to reunite them once again. After six long years, destiny has finally placed Nino, Momo, and Yuzu in the same high school. However, the passage of time has changed many things in their lives—while Nino relentlessly attempts to fulfill her childhood promise with the boys, Yuzu's feelings for her from the past resurface, and Momo goes to great lengths to prevent a reunion with Nino. Through music, will they be able to mend their friendship and overcome all the feelings involved in this complicated love triangle?

High school freshman Hiromi joins the tennis club because of her admiration for Ryuzaki. Ryuzaki is a senior, who's the best tennis player on the team and also nicknamed "Ochoufujin", ("Madame Butterfly"), because of her elegance on the tennis court. However, the new coach, Jin Munakata, wants the inexperienced Hiromi to play in a forthcoming tournament. Due to this, Hiromi considers quitting tennis for good but, in the depth of her soul, she soon realizes that she loves tennis after all. She returns to the club and, under Munakata's coaching, her talent starts to bloom. In the end, Hiromi develops a strong emotional bond with her coach, not knowing that Munakata is risking his life because of a chronic illness. (Source: AnimeNfo)

Special episodes included in BD.

A side story that reveals the investigative notes that Atsuko, the younger sister of the main character Akihiko Chuzenji, wrote about the brutal dismembering incidents in the main story. (Source: ANN)