Ryuki sat at the desk and began to write about all the women in his life.
First is his mother, Fumiko. He already has a sexual relationship with her, and getting her into the harem wasn't much of a problem.
Second is Saki. He has already expressed his love for her, but there's a long way to go before sex.
Third is Asuka, Yuta's sister and his friend, also a heroine. Currently, he has a good relationship with her, and to be in a relationship with her, he just has to play games like he, Rena, and Asuka used to play.
Fourth is Rena. For Rena, it's the same: play games, have sex, and then get into a relationship.
Fifth is Ruby. He just has to confess and have sex; that's all.
Sixth is Michiko, Yuta and Asuka's mother. He is in a relationship with her right now, and it's good. Getting her to agree to the harem is also easy.