Love Shuffle

• Kanjiya Shihori as Kagawa Mei

Mei is the fiancée of Kei, even though he is her first love she feels that their relationship has drawn the life out of the man she fell in love with. She breaks off the engagement to save Kei from further suffering at the company he hates. She genuinely loves him and wants him to be happy. Throughout the drama she tries to experience new things and grow as a woman, since she has only loved one man her entire life, Kei. She starts to feel a connection with Yukichi but chooses Kei and wishes to get married as planned at the end of the shuffle.

• DAIGO as Oishi Yukichi

Yukichi is the boyfriend of Airu, he is extremely wealthy and always carries around a suitcase full of cash. He is quick to spend money often buying out whole restaurants for dates. He was often bullied as a child and even thought of committing suicide. Since then he becomes very attached to people and tends to go overboard when he likes someone. He is deeply in love / obsessed with Airu. He sees nothing wrong with using his money to get his way or spy on people. Even putting a tracking device on Kei's cellphone. At first he joins the shuffle to win Airu's heart but he has no problem sleeping with Reiko and later falls in love with Mei after he overhears her say she started to like him. He then begins to try and break up Kei and Mei, even thought he and Kei have become best friends. They eventually team up so Yukichi can win Mei's heart and they marry instead of she and Kei.

• Kojima Hijiri as Kamijo Reiko

Reiko is the rich married lover of Ojiro. She joins the shuffle claiming she wants to experience love and to feel beautiful since her husband is cheating on her with a younger woman. She has the theory that it is okay if she sleeps with other men because her soul mate is her husband and that will never change. Later it is revealed that her husband knew about the shuffle and was okay with it, they participate so Reiko can conceive a child. She becomes pregnant after spending one week with each of the men. She tells the men it doesn't matter who the father is since it will be her husband's child. In the end it is revealed that she wishes to divorce her husband since he is cheating on her and never truly loved her. She does confide that the child's father is actually Masato since she never had sex with Kei or Yukichi and the timing isn't right for it to be Ojiro's since they haven't slept together since before the shuffle started.

• Yoshitaka Yuriko as Hayakawa Kairi

Kairi is a young art genius who paints the image of Thanatos. She is a patient of Masato's, she claims to see Thanatos everywhere she goes and he wishes for her to kill herself. She has made a promise that she won't commit suicide before her 20th birthday. She joins the shuffle simply because Masato tells her too. She is very emotionless and doesn't speak often. As the shuffle goes on and she dates the different men she begins to react more and express emotions. She smiled and seemed happy after Kei won her a defective panda plushy from a claw game during their date. She does fall in love with Ojiro after their week together, even though he seems indifferent and mocks her for "pretending" to want to die. She has sex with him and later follows him around as if his pet. Even though she still wishes to die she does begin to open up thanks to the attention and affection from Ojiro. He also reluctantly falls in love with her. During her 20th birthday party Ojiro makes her promise that she will only die after he does and she will stay by his side until then. The next day she vanishes, it is assumed that she killed herself when actually Masato told her to leave so she could see that effect her death would have on those who love her. After seeing Ojiro mourn her she decides to stay with him and not die until he does.