Ayako Katsuragi has spent the past decade raising her niece Miu as her own daughter, ever since her sister and brother-in-law died in an accident. Now that Miu is in high school, Ayako keeps an anxious eye on the boys around her, above all Takumi Aterazawa, the twenty-year-old neighbor who has tutored Miu for years and seems to be building up to a confession. He finally makes it, and the person he has been in love with all along is Ayako, not Miu.