Immoral sisterhood, wife-swapping, let's see which is more perverted, my wife or your wife. Aoki Rei, Hanyu Ki. DTKM-026

Two brothers, tired of having sex with their own wives, one day thought they might as well swap wives and have sex with each other. They then deliberately had sex near each other to increase their pleasure, but it still wasn't exciting enough, so they decided to have a competition to see which wife was more perverted...