A new mother who suddenly became a mother a year ago. A son is confused when he is introduced to his young and beautiful girlfriend's mother-in-law. Lustful for her mother-in-law's body, her son's sexual desire continues to accumulate...One day, when he was thinking of leaving home as he reached his limit, his girlfriend's family decided to go on a trip to a hot spring. At the hot spring inn, the son's patience reaches its limit, and he fondles and sucks Akari's breasts, licks her private parts, and mercilessly penetrates her. Even though it's my son-in-law...I know it's no good.