Her husband works alone and lives in a rural area. Reiko (46), a married woman who lives alone, works as an exercise instructor at home. She is currently giving lessons to two male students, Miyazaki (40) and Okumura (21). Okumura is bothered by Reiko's overly sexy looks and poses. Miyazaki, on the other hand, is taking the lessons seriously. Okumura is jealous of Reiko's tenderness towards Miyazaki and leaves first. When Reiko and Miyazaki are left alone together, the mood becomes bewitching, and Reiko's lust rises and she sucks Miyazaki's cock. A few days later, Okumura sees them making love and asks to be a part of it, which Reiko gladly accepts...