His mother's best friend , Ririka, comes to visit. While his mother prepares for the party, Kotaro ends up talking to Ririka. Her beauty, her deep cleavage, her long, slender limbs... Kotaro tries desperately not to be swept away by her mature sex appeal, but he can't hold back any longer and starts fantasizing about Ririka using Ririka as a stimulant. Furthermore, Ririka sees his fully erect penis...