On her 20th birthday, Arito warmly celebrates with Yume, making her feel this night will be special—even though their relationship hasn't yet turned intimate. But Yume has been hiding a secret: she's still a virgin, torn between her feelings for Arito and her fears. Though anxious about losing her virginity, she's enveloped by his tenderness and warmth, drawing their hearts closer than ever. This film captures the bittersweet, tender moment of a first time.