After his sister's death, high school student Aoto lives with his brother-in-law Takashi, whom he is secretly in love with. Takashi has to go on a business trip and asks his friend Masayuki, a devilishly handsome older guy, to keep an eye on Aoto. Aoto doesn't know how to take the flirty Masayuki, and wonders if the portion of his heart he has closed will ever be open again?