Never tell your husband that you got pregnant after being fucked by your father-in-law. (Mukai Ran JUQ-251)

Lan, pressured by her aunt to give birth to a grandson as soon as possible, is on a family trip to a hot spring. However, she is ordered by her aunt to abstain from sex for a month in preparation for having a child. On the day of the trip, her husband refuses to have sex with her. Meanwhile, her adoptive father also wants to be intimate with his wife, but is also refused. Unable to control their desires, they go to the hot spring to relax. Then, the adoptive father accidentally sees Lan bathing...