Reunited Worlds

Reunited Worlds is a South Korean television series starring Yeo Jin-goo, Ahn Jae-hyun, and Lee Yeon-hee. It aired on SBS from July 19 to September 21, 2017, for 40 episodes.

Synopsis
Sung Hae-sung (Yeo Jin-goo) is a senior high school student. On Hae-sung's birthday, his girlfriend Jung Jung-won (Jung Chae-yeon) prepares a surprise party for him at his house. To keep Hae-sung away from the house while they prepare, Jung-won asks him to go to their school and retrieve her wallet. There, he walks into a shocking scene. While trying to get help, he is hit by a car and dies. 12 years later, Hae-sung wakes up at the roof of his school building, and he meets Jung-won (Lee Yeon-hee) again. Although Jung-won and Hae-sung were born in the same year, the two childhood friends end up being 12 years apart because they have aged at different places (worlds) for some strange reason. Now Jung-won is a 31-year-old woman, but Hae-sung is still a 19-year-old boy. With the assistance of his friends and Jung-won, Hae-sung sets out to make things right for his family and solve the mysteries surrounding his death and resurrection.

Main

 * Yeo Jin-goo as Sung Hae-sung (19-years-old)
 * Lee Yeon-hee as Jung Jung-won (31-years-old)
 * Jung Chae-yeon as young Jung-won
 * Ahn Jae-hyun as Cha Min-joon (34-years-old)

Hae-sung and Jung-won's friends

 * Shin Soo-ho as Kil Moon-shik (31-years-old)
 * Kim Min-sang as young Kil Moon-shik
 * Electronic Service Center employee.


 * Lee Si-eon as Shin Ho-bang (31-years-old)
 * Park Sung-joon as young Shin Ho-bang
 * Police officer.


 * Kim Jin-woo as Cha Tae-hoon (31-years-old)
 * Choi Soo-han as young Cha Tae-hoon
 * The chief executive of a department store. Cha Min-joon's younger half-brother.


 * Park Jin-joo as Hong Jin-joo (31-years-old)
 * Park Jin-soo as young Hong Jin-joo
 * Roaming yoga instructor.

Hae-sung's siblings

 * Yoon Sun-woo as Sung Young-joon (30-years-old)
 * Park Joon-mok as young Sung Young-joon
 * Chest surgeon. Sung Hae-sung's younger step-brother.


 * Kim Ga-eun as Sung Young-in (26-years-old)
 * Lee Young-eun (actress, born 2004) as young Sung Young-in
 * Employee in a clothing department store. Sung Hae-sung's younger step-sister.


 * Kwak Dong-yeon as Sung Hae-chul (25-years-old)
 * Jeon Jin-seo as younger Sung Hae-chul
 * Sung Gong-joo's father. Sung Hae-sung's real younger brother


 * Kim Hye-jun as Sung Soo-ji (19-years-old)
 * Choi Yoo-ri as young Sung Soo-ji
 * High school senior. Sung Hae-sung's younger half-sister.

Hae-sung's family

 * Kim Han-na as Sung Gong-joo (6-years-old)
 * Sung Hae-sung's niece. Sung Hae-chul's daughter.


 * Park Seung-tae as Kang Mal-yi (78-years-old)
 * Sung Hae-sung's grandmother.

Extended

 * Park Yeong-gyu as Cha Kwon-pyo (65-years-old)
 * Cha Min-joon and Cha Tae-hoon's father. Cheongho High School Chairman.


 * Bang Eun-hee as Yoon Mi-na (55-years-old)
 * Cha Tae-hoon's mother. Cha Kwon Pyo's second wife.


 * Han So-hee as Lee Seo-won (27-years-old)
 * Sung Young-joon's girlfriend. Hospital Director's daughter. Fashion journalist.


 * Kyeon Mi-ri as Son Myung-ok (55-years-old)
 * Lee Seo-won's mother.


 * Kim Byung-se as Lee Gun-chul (58-years-old)
 * Lee Seo-won's father. Hospital director.


 * Ahn Gil-kang as Ahn Tae-bok
 * Lee Je-yeon as Yang Kyung-chul


 * Kim Hee-jung as Nam Yoo-min
 * Sung Gong-joo's biological mother


 * Min Joon-ho as Sous-chef (30-years-old)
 * Choi Sung-min as Dong-hyun
 * Ahn Sol-bin as Nam Soon-ji
 * Kim Young-woong as Moneylender
 * Bae Jin-woong as Moneylender
 * Jung Wook
 * Kim Dong-kyoon
 * Baek Ji-won as Landlord
 * Han Eun-seon
 * Oh Jung-tae as Accessory salesman
 * Park Hyun-sook as Cha Min-joon's maternal aunt
 * Kang Sung-min as Park Dong-seok / Jason Park

Special appearances

 * Seo Yi-sook as Jung Jung-won's mother
 * Yoon Mi-ra as Lady Doh
 * Jeon Gook-hwan as Ha Do-kwon

Production
The series is the third collaboration between writer Lee Hee-myung and PD Baek Soo-chan, who worked on A Girl Who Sees Smells (2015) and Beautiful Gong Shim (2016).

Ratings

 * In the table above, the blue numbers represent the lowest ratings and the red numbers represent the highest ratings.
 * NR denotes that the drama did not rank in the top 20 daily programs on that date