Kazuya, a lodger, gradually finds himself falling for his landlady Yasuko, who always greets him with a gentle, warm smile. As he experiences her kindness, Kazuya's feelings deepen into love. Through the playful meddling of Yasuko's friend Mayumi, his emotions begin to stir even more. Kazuya is pure and innocent, while Yasuko struggles with complicated feelings within her current relationship. After breaking up with her boyfriend, Yasuko slowly begins to realize her growing affection for Kazuya. "Yasuko-san..." "Because Kazuya-kun came..." As these words are exchanged, Yasuko's chest becomes damp with tears. A tender, heartfelt love story draws their souls closer together.