X: A mysterious man who is later revealed as the father of Na-na. She is the embodiment of Do-hyun's childhood fears as well as Ri-jin's younger self.
Na-na (Cha Do-hyun): A 7-year-old girl who owns a teddy bear named Nana and revealed that her name is Cha Do-hyun.
She appears when Cha Do-hyun undergoes a great deal of pain or mental stress, and needs to endure it clandestinely.
Ahn Yo-na : An extrovert and mischievous 17-year-old girl who loves idols.
He first appeared when Cha Do-hyun attempted to commit suicide when he was in high school.
Ahn Yo-seob : A suicidal, intelligent 17-year-old boy who is an artist.
The name "Perry Park" came from the promise Do-hyun (Joon-young) made to his father, which is to buy a boat named Perry Park Boat for him. He appears when Cha Do-hyun reminisces the sweetside of his father before they came back into the mansion.
Perry Park: A 40-year-old man with an affinity for fishing and building bombs.
Se-gi endures all of Do-hyun's pain as he is the only identity to have all of Do-hyun's memories. He may be violent, but he never hurts children and women.
Shin Se-gi: A vehement young man with a devil-may-care demeanor who appears when Cha Do-hyun experiences violence.
In Episode 17, it was revealed that Cha Joon-young is his real name. However, after realizing that he suffers from dissociative identity disorder 11 years ago, he has been desperately trying to hide this fact from his families and friends.
Lee Do-hyun as child Cha Do-hyun (Cha Joon-young)Ī wealthy businessman with a warmhearted personality who loves to help others.
Ji Sung as Cha Do-hyun (Cha Joon-young).
Can Do Hyun take control over his condition before one of his seven identities takes control of him instead? But Ri Jin's twin brother, Oh Ri On ( Park Seo-joon), is a writer who is determined to uncover the unscrupulous lives of the rich and starts following Do Hyun around. He tries to regain control over his life with the help of Oh Ri Jin ( Hwang Jung-eum), a beautiful first-year psychiatric resident who helps him secretly. Cha Do Hyun ( Ji Sung) is a third-generation business heir who developed dissociative identity disorder (previously known as multiple personality disorder) in the aftermath of several life-threatening traumatic events. The human body is capable of all sorts of things to survive difficult situations.