Hello, My Twenties!

Hello, My Twenties! is a South Korean television series starring Han Ye-ri, Han Seung-yeon, Park Eun-bin, Ryu Hwa-young, Park Hye-su, Ji Woo and Choi Ara. It aired on JTBC from July 22, 2016 to October 7, 2017.

Synopsis
A slice-of-life story about five girls who live together in a sharehouse called "Belle Epoque" and how they connect over the growing pains in their youth. It is based on the issues that younger generations are likely to face in South Korea.

Main

 * Park Hye-su (season 1) and Ji Woo (season 2) as Yoo Eun-jae
 * A 20-year-old Psychology major student who comes from the countryside.


 * Han Seung-yeon as Jung Ye-eun
 * A 22-year-old Culinary Arts major with a religious background.


 * Han Ye-ri as Yoon Jin-myung
 * A 28-year-old hardworking business major with a complicated family situation.


 * Park Eun-bin as Song Ji-won
 * A 22-year-old Journalism major, a quirky adventurous roommate who claims to have the ability to see ghosts.


 * Ryu Hwa-young as Kang Yi-na (season 1; guest season 2)
 * A 24-year-old sugar baby with expensive taste. She eventually works hard to be a career woman.


 * Choi Ara as Jo Eun (season 2)

Recurring

 * Yoon Park as Park Jae-wan (season 1; guest season 2)
 * Jin-myung's love interest, Italian restaurant chef.


 * Choi Deok-moon as Oh Jong-gyu – Yi-na's mystery man
 * Ji Il-joo as Go Doo-young – Ye-eun's abusive ex-boyfriend
 * Shin Hyun-soo as Yoon Jong-yeol – Eun-jae's boyfriend
 * Son Seung-won as Im Sung-min – Ji-won's male friend
 * Yoon Jong-hoon as Seo Dong-joo – Yi-na's friend
 * Kim Min-seok as Seo Jang-hoon (season 2)
 * Deputy of the share house, Belle Epoque's owner, Jo Eun's love interest.


 * Lee You-jin as Kwon Ho-chang (season 2)
 * Ye-eun's love interest; an engineering student who knows nothing about dating.


 * Ahn Woo-yeon as Heimdallr / Lee Jin-kwang (season 2)
 * A member of an idol group Asgard who is five years into his debut, but yet to reach stardom.


 * Lee Ji-ha as Ho-chang's mother
 * Kim Hyo-jin as Yoon Jin-myung's mother
 * as Ahn Jung-hee – Yoo Eun-jae's mother
 * Kim Yong-hee as dentist – Kang Yi-na's third lover
 * as restaurant manager
 * as Jo Hyun-hee – restaurant waitress
 * Han Jeong-woo as Kang Yi-na's second lover
 * Song Ji-ho as Kang Yi-na's stalker
 * as Han Yoo-kyung – Jung Ye-eun's friend
 * Choi Bae-young as Song Kyung-ah – Jung Ye-eun's friend
 * Kim Si-eun as young Yoon Jin-myung
 * Yoon Yong-joon as Shin Yool-bin – Yoo Eun-jae's crush
 * Kim Kyung-nam
 * Jung Yi-seo as Ye-eun's classmate
 * as insurance employee
 * as dancing student
 * as Song Ji-won's father
 * Kwon Eun-soo as Yoon Jong-yeol's junior
 * as Yoo Eun-jae's aunt
 * Shin Se-hwi as Ahn Ye-ji, Jo Eun's friend
 * Jo Byeong-kyu as Jo Chung-han
 * Kim Ye-ji as Ye-ji
 * Yoon Sa-bong as Ho Chang's sister
 * Seo Ye-hwa as Su & Su receptionist
 * Go Min-si as Oh Ha-na

Special appearances
Season 1: Season 2:
 * Moon Sook as home owner grandmother
 * Ji Il-joo as Go Doo-young
 * PENTAGON as members of idol group Asgard
 * A.C.E as members of idol group The Fifth Column
 * Ji Hye-ran
 * Yoon Kyung-ho as Moon Hyo-jin's boyfriend
 * Kim Jung-young as Song Ji-won' mother
 * Kim Hak-sun as Jo-eun's father

Production
On February 16, 2017, the series was renewed for a second season. It was announced that Ryu Hwa-young would only make a cameo appearance, and that a new actress would be cast as the fifth girl of the Belle Epoque.

Originally, it was expected that all five main roles would be the same from the previous season. However, early on Ryu Hwa-young was removed from the main cast due to her being exposed as a bully in T-ara. Instead, a new character, Jo Eun, was created to fill the five-person dynamic of the show. Park Hye-soo was also supposed to be part of the main cast, but due to a scheduling conflict, she stepped down from the role. Unlike Ryu Hwa-young, this happened late into pre-production and it was decided that another actress would play her character Yoo Eun-jae; Ji Woo was cast.

Onew was originally cast in the role of Kwon Ho-chang, but he stepped down in light of controversy surrounding him ten days before the drama's premiere, and was replaced with Lee Yoo-jin.