Uwaki soukanzu: Nokezori gyaku aibu

浮気相姦図 のけぞり逆愛撫

Also known as 浮気天国 いけない牝尻, Uwaki tengoku: Ikenai mesu shiri

On the morning of their wedding anniversary, Tatsuhiko's diamond ring is discovered by his wife, Yumiko. To make matters worse, it also happens to be the birthday of Ruka, with whom he is having an affair, leading to a huge commotion. Just then, a massive earthquake strikes, and Tatsuhiko and Ruka's bodies are swapped! Ruka (who is actually Tatsuhiko) is now being pursued by his subordinate, Satoda, while Tatsuhiko (who is actually Ruka) is being pursued by Yumiko.