Hitozuma no yubi undō nōkō o mune taiken

Original title: 人妻の指運動 濃厚お胸体験

Sayaka lives alone while her husband is away on a business trip overseas. Then her ex-boyfriend, Tatsuo, suddenly shows up and reluctantly lets him stay with them. Tatsuo comes from a wealthy family and a friend of his has approached him with a strange investment idea...