The other couple tricked/forced FH into cheating making her believe her husband was having sex with her friend, it was all a ruse with the audio as they were just played ping-pong.
>Two couples, Sakura and Hiroto, and Henri and Kai, were on a hot spring trip together. >At first glance, they seem to be four different types of people, but Sakura, Hiroto, and Kai are classmates from university. >This time, they invited Kai's girlfriend, Henri, and it was their first group trip. At the hot spring, Sakura was a little overwhelmed by Henri, who has a free-spirited personality. Sakura was at the mercy of Henri, who openly talked about his sex life. And after dinner... >When Hiroto wanted to go for a walk to work up an appetite, Henri said he wanted to come with him. Hiroto readily agreed, and Kai didn't try to stop him. In the end, Sakura and Kai stayed in the room together. But it was all planned...