The boys in the movie are so happy to have extremely lustful cousins. The cousins not only help them clean their rooms and arrange their belongings neatly, but they are also great sex tools if they know how to exploit them properly. Of course, for guys who are addicted to sex like them, they cannot ignore them. The cousins constantly reveal sensitive areas such as their firm buttocks and big breasts, causing the older brother to accidentally see them while there are only two people in the room. So it is no wonder that incestuous love affairs often happen in Japan, which is very clear in the 3 parts of the movie.