Its Okay to Not Be Okay Cast featuring Kim Soo-hyun, Seo Ye-ji, Oh Jung-se, and more in a poignant tale of love and healing.
Table of Contents
Introduction

It’s Okay to Not Be Okay features a remarkable cast that brings emotional depth and complexity to this poignant drama. Leading the series are Kim Soo-hyun as Moon Gang-tae, a caregiver at a psychiatric hospital struggling with his own past while caring for his older brother. Seo Ye-ji plays Ko Mun-yeong, a successful yet troubled children’s book author who confronts her emotional wounds throughout the story. Oh Jung-se portrays Moon Sang-tae, Gang-tae’s older brother with autism, whose bond with Gang-tae is central to the emotional arc. Supporting them are Park Gyu-young as Nam Ju-ri, a nurse who harbors unspoken feelings for Gang-tae, and Jang Seung-jo as Lee Sang-in, a psychiatrist who plays a key role in the characters’ healing processes. Each actor brings their own unique depth to these multifaceted characters, making the show a deeply moving exploration of mental health, trauma, and recovery.
Its Okay to Not Be Okay cast
1. Kim Soo-hyun as Moon Gang-tae
- Character: Moon Gang-tae is the main lead of the series, a caregiver at a psychiatric hospital. He is a kind, reserved man who has spent his life taking care of his older brother, who has autism. Throughout the series, Gang-tae faces challenges related to his own mental health and emotional struggles.
- About the Actor: Kim Soo-hyun is a widely celebrated South Korean actor who gained immense fame through roles in Dream High (2011), My Love from the Star (2013), and Producer (2015).
2. Seo Ye-ji as Ko Mun-yeong
- Character: Ko Mun-yeong is a bestselling children’s book author with a dark past and a troubled emotional state. She is known for her cold, blunt demeanor, but as the series progresses, her complexity and vulnerability become more apparent.
- About the Actress: Seo Ye-ji has gained significant attention for her roles in Save Me (2017) and Lawless Lawyer (2018), but this role in It’s Okay to Not Be Okay catapulted her into further stardom due to her strong, transformative performance.
3. Oh Jung-se as Moon Sang-tae
- Character: Moon Sang-tae is Gang-tae’s older brother who has autism. He has a deep love for his younger brother and shares a unique bond with him. Sang-tae’s character adds a lot of emotional depth and serves as a central figure in Gang-tae’s journey.
- About the Actor: Oh Jung-se has been recognized for his versatility and depth in acting. Before this role, he had supporting roles in various dramas but became a household name due to his portrayal of Sang-tae.
4. Park Gyu-young as Nam Ju-ri
- Character: Nam Ju-ri is a nurse at the psychiatric hospital where Gang-tae works. She is warm-hearted and supportive, though she also harbors her own emotional burdens, particularly her unrequited love for Gang-tae.
- About the Actress: Park Gyu-young is known for her roles in The Devil Judge (2021) and Sweet Home (2020), and It’s Okay to Not Be Okay helped her gain further recognition for her charming and nuanced performance.
5. Jang Seung-jo as Lee Sang-in
- Character: Lee Sang-in is a psychiatrist who works with Gang-tae at the hospital. He plays an important role in helping the characters deal with their trauma, especially as he interacts with the main leads in their healing process.
- About the Actor: Jang Seung-jo is known for his supporting roles in various K-dramas and films, and he earned praise for his portrayal of a compassionate, yet reserved, psychiatrist in this series.
6. Kim Joo-ryoung as Matron
- Character: Matron is a figure who works at the hospital and plays a somewhat comedic but also empathetic role, providing support to the characters while showing her own layers as the series unfolds.
- About the Actress: Kim Joo-ryoung has had a steady career in supporting roles and has gained attention for her performances in Squid Game (2021), though her role in It’s Okay to Not Be Okay also stood out.
supporting characters:
2. Kang Bu-ja as Ko Mun-yeong’s mother
- Character: She plays a significant part in revealing Ko Mun-yeong’s troubled past, which plays a key role in the protagonist’s development and emotional healing.
3. Lee Seung-joon as Lee Joo-hyun
- Character: Lee Joo-hyun is the head of the psychiatric hospital where Gang-tae works. He appears in a supportive yet slightly distant capacity, helping to guide the care of patients while interacting with the main characters.
4. Park Jong-hwan as Ko Mun-yeong’s father
- Character: His character adds to the complexity of Mun-yeong’s past, contributing to the challenges she faces and the trauma that she must overcome during the course of the series.
5. Yoon Ji-on as Jo Jae-soo
- Character: He is a member of the hospital staff and is often seen working alongside Gang-tae and the other characters, providing subtle yet significant emotional support throughout the series.
Conclusion
The cast of It’s Okay to Not Be Okay is undeniably one of the key elements that makes the series so impactful. From the heart-wrenching performances of the main leads, Kim Soo-hyun and Seo Ye-ji, to the emotional depth brought by supporting characters like Oh Jung-se and Park Gyu-young, the actors bring to life a story that resonates deeply with audiences. The complex portrayals of mental health, trauma, and healing are made even more poignant by the talented ensemble cast. Each character, whether main or supporting, adds to the rich narrative, ensuring that It’s Okay to Not Be Okay is not just a drama, but a transformative experience that encourages empathy, understanding, and personal growth.
My Love from Another Star Cast & Their Role (2013-2014)
(FAQs)
Who plays Moon Gang-tae in Its Okay to Not Be Okay cast?
Kim Soo-hyun plays Moon Gang-tae, a caregiver at a psychiatric hospital who grapples with his own emotional struggles while taking care of his older brother.
Who is Ko Mun-yeong, and which actress portrays her?
Seo Ye-ji portrays Ko Mun-yeong, a successful but troubled children’s book author who has a complex past and a difficult emotional journey throughout the series.
Who plays Moon Sang-tae in the series?
Oh Jung-se plays Moon Sang-tae, Gang-tae’s older brother with autism. His relationship with Gang-tae is central to the show, providing emotional depth and insight into the struggles of caregiving.
What role does Park Gyu-young play?
Park Gyu-young plays Nam Ju-ri, a nurse at the psychiatric hospital who secretly loves Gang-tae and provides warmth and support throughout the series.
Who is Lee Sang-in, and who plays him?
Jang Seung-jo portrays Lee Sang-in, a psychiatrist at the hospital who plays an important role in helping the main characters process their trauma and begin healing.
Who plays Matron in the hospital?
Kim Joo-ryoung plays Matron, a staff member at the psychiatric hospital who brings both comedic relief and emotional support to the characters.
How did Kim Soo-hyun’s role in It’s Okay to Not Be Okay differ from his previous roles?
In this series, Kim Soo-hyun takes on a more emotionally complex and nuanced character as Moon Gang-tae, which was a departure from his previous roles in lighter, more romantic comedies.
Did Seo Ye-ji receive any recognition for her role in the series?
Yes, Seo Ye-ji received widespread acclaim for her portrayal of Ko Mun-yeong, a character who struggles with her own mental health while navigating a dark past. Her performance was highly praised and earned her numerous awards.
Are there any notable supporting actors in It’s Okay to Not Be Okay?
Yes, the supporting cast includes Kim Joo-ryoung as Matron, Lee Seung-joon as Lee Joo-hyun, and Yoon Ji-on as Jo Jae-soo. They all contribute significantly to the story’s emotional depth.
What makes the cast of It’s Okay to Not Be Okay so special?
The cast is praised for their powerful performances and the way they deeply connect with the themes of the drama. The ensemble brings authenticity and emotional resonance, making the story about mental health and healing even more impactful.