Married for half a year. The Kasumi couple still feels like newlyweds, but things get awkward when the husband's stepson, Fumiya, comes back for a visit. Reiko, the uneasy stepmother, one day rushes to help Fumiya who collapses due to dehydration while bathing. Unable to take her eyes off his impressive physique, Reiko inadvertently starts to touch him. Fumiya, noticing, persuades her to lead him to ejaculation. However, unsatisfied, Fumiya shows off his youthful, vigorous, and insatiable penis to Reiko again...
