Hiroki starts working part-time at a restaurant run by a friend's parents, but as he works with his mother, Natsu, before he knows he becomes aware of her as the opposite sex. Then one night, after work, I missed the last train and had to stay at Natsuko's house for one night... Unlike at work, Hiroki desperately hides her excitement as she wears a braless bra, showing off her plump body generously. However, Natsuko, whose drunken, hidden sexual desire exploded, couldn't hold it in and led his hand to her chest...