Ryoko, the wife of my older brother who is an obstetrician, and Nanako, the wife of my younger brother who is an internist. - The two of them have a little secret... They are not satisfied with the behavior with their husbands, so they each decide to go to the doctor for a reason and secretly try to exchange husbands. - Nanako said it was a pregnancy test, and her brother-in-law palpated her genitals on the examination table, quietly enjoying the pleasure. - Ryoko also kept her crotch moist as she examined her brother-in-law. - The wife came to see the doctor again...One day, Ryoko and Nanako passed by the brothers who were chatting in the office after the hospital had closed. - The brothers, who couldn't talk to each other, listened to their wives' conversations with their breath in. When they heard that each of them had sex with their wives, things started to get tense for a moment, but then a useless trainee doctor appeared...