Naoyuki Kitamura is a sophomore in high school. He has a cute gal girlfriend, Eri Fujino. She also has a wonderful mother, Miyuki. Although Eri and Miyuki are mother and daughter, they are polar opposites. While the daughter is a blonde, brown-skinned gal, the mother is a fair-skinned, neat and tidy lady. The only thing they share in common, however, is the size of their breasts. No, the mother is even more impressive. But then, one day, Miyuki, the earnest mother, decided to confront her daughter’s boyfriend, Naoyuki…