Hiroyuki can hardly contain his excitement when his mother's friend, Kotone, comes to tutor him. Not only does she have a pretty face, but her big tits stimulate his unlimited sexual desire even more... Then, Kotone noticed his eyes on her and teased him as if she wanted to relieve her frustrated frustration. Since then, Kotone, who visits him every now and then under the guise of tutoring him, continues to stimulate his inferiority complex and enjoys the hidden pleasure that she cannot experience with her husband....