Kenta was extremely troubled. The cause of this was his sister-in-law, Rena's strange behavior. It was fine that she had come to help with the housework while his wife was pregnant and visiting her hometown. But after that, she started doing a lot of strange things. She came into the bathroom naked saying she was going to wash his back... (Could she really be trying to seduce him? No, that couldn't be the case.) Kenta concluded that Rena's strange behavior was just teasing him. Feeling frustrated, he went to bed...and then Rena came in...