"What?! What did you just say?" Reiko couldn't believe her ears and asked again. "What do you mean, you're still a virgin?" Her son Naoki was getting married, but he said he still had no experience with a woman. "You've had other girlfriends up until now, haven't you? And yet you've never done it..." It was an unexpected confession. "I thought you'd been sighing a lot lately, but..." Reiko was at a loss for words, but with the wedding just around the corner, she realized that things wouldn't go well if she continued like this, and came up with the idea of using her own body to teach him about sex...