SONE-669 When the housewife next door hangs her panties out on the balcony in the afternoon, it's a sign that her husband is not around. - Rei Kuroshima

(Today, panties are hanging out to dry on the balcony. It's a sign that we're going to have sex.) Newly married Rei is sexually frustrated but feels suffocated in her relationship with her conservative husband. One day, Nakata, a middle-aged man, moves in next door. After meeting him, Rei's desires are gradually released. Rei sends a signal to him by hanging her underwear out to dry on the balcony, out of her husband's sight, and the two begin a secret relationship. She invites him into her room on the pretext of repairing the air conditioner, and they meet up repeatedly while her husband is away, and Rei gradually becomes bolder.