Reiko's husband has loved his beautiful wife as deeply as ever since they met, but age has recently left him struggling to get hard. Afraid she may lose interest in him, he finally turns to medication. By a cruel twist of fate, however, Reiko and her adult son accidentally drink the aphrodisiac-laced beverage. Though the room is not hot, their bodies begin to sweat and Reiko feels an ache deep inside. Overcome by burning desire, the mother and her adult son give in to their forbidden urges.