Sister Reiko and younger sister Akari. They are famous for being close sisters who both have families and live nearby, but in reality, they have an incredibly strong sex drive and were raised competing with each other over who could please a man more. In this context, when they realized that each other's sons had problems, the two came up with an idea... It was to see which of them could solve the problem. In other words, it was about which of them could satisfy their sons, for the purpose of fulfilling their sexual desires…
