Yui is 25 years old and has been married for two years. She boards a sleeper train from Sapporo to Ueno. The married woman has not had sex for a year. She stands in the swaying car, wiggling her hips and greedily enjoying sex. The married woman's sexual desire burns more and more without showing any sign of waning. In the morning shower, she presses her body against the man, teasing him. In a running, closed room, the elegant married woman takes the man in her mouth, giving in to her lust...