It’s Okay To Not Be Okay starring Seo Ye-Ji and Kim Soo-Hyun is definitely not like any other romantic K-dramas we’ve seen before. Beyond the swoon-worthy moments lie a thrilling mystery that often feels detached yet ethereal — made even better with Seo Ye-Ji’s character's gorgeous wardrobe. Plus, it remains well-balanced for depicting heart-wrenching stories about the realities of mental health disorders.
This K-drama, which only has two more episodes left as of writing, has made us laugh, cry, and feel heartbroken — sometimes, all at once. But what it’s truly great at is delivering shocking revelations that we’ve probably seen coming yet still leave us in disbelief.
Before this K-drama reaches its conclusion this weekend, here’s a lineup of the best It’s Okay Not To Be Okay plot twists — from Sang-Tae’s hidden anger to the truth about Ko Mun-Yeong’s mother.
Nurse Park Haeng-Ja is Ko Mun-Yeong’s mother, Do Hui-Jae
We’re just gonna go ahead and say it: the kind Head Nurse Park Haeng-Ja is Ko Mun-Yeong’s mother, Do Hui-Jae? Yes, it’s true! Probably one of the biggest reveals of the series, the truth about Ko Mun-Yeong’s mother unfolded at the end of Episode 13.
Head Nurse Park has always been a kind and just figure in the OK Psychiatric Hospital, even helping Sang-Tae calm down and make up with Gang-Tae during their major fight in Episode 9. She’s also the voice of reason who contrasts Dr. Oh Ji-Wang and his quirky methods, making them a good tag team to manage the facility.
Yes, there’s definitely a feeling of betrayal when we found out that she actually had plastic surgery to be unrecognisable to her husband (and Mun-Yeong’s father) Ko Dae-wan so that she can watch him slowly fall to his demise due to his disease. Based on the events of the latest episode, it seems like she's after our main trio next. Creepy!
Mun-Yeong’s mother killed Moon Gang-Tae and Sang-Tae’s mother
We also learned that the 'butterfly', which Sang-Tae has always associated with their mother's killer, is in reference to a one-of-a-kind brooch specially designed by Do Hui-Jae herself. Hui-Jae was wearing it when Sang-Tae witnessed her mother's murder and was the only thing in his line of sight when Hui-Jae threatened to kill him next if he squeals, leading to his obscured memory of the incident.
After learning the truth, Gang-Tae attempted to protect both his brother and Mun-Yeong from the revelation, but Mun-Yeong still found out about it after the vandalism incident in the hospital. Devastated about their ill-fate, Mun-Yeong drove Gang-Tae away because of guilt over her mother's crime, leading to a very emotional Episode 14.
Sang-Tae’s hidden anger towards Gang-Tae
Another dramatic It’s Okay To Not Be Okay plot twist we got in the earlier episodes is the revelation of Sang-Tae’s hidden anger towards Gang-Tae. After he got upset when the latter left him to be with Ko Mun-Yeong overnight, Sang-Tae lashed out at his brother for wanting him dead when they were younger and even leaving him in the river to drown.
We predicted that a major spat between the two would happen, but we assumed it would be Gang-Tae turning up the emotions rather than his brother. While that very moment was foreshadowed early on in Episode 9, watching it unfold onscreen — with special thanks to the incredible acting of Oh Jung-Sae, Kim Soo-Hyun and Seo Ye-Ji — was surely enough to deliver both tears and goosebumps.
Kan Pil-Wong’s PTSD
K-dramas are known for delivering amazing tearjerking side stories. However, the plot twist on It's Okay Not To Be Okay about patient Kan Pil-Wong’s backstory is one that truly triggers the waterworks albeit its briefness. As one of the oldest and kindest patients in the OK Psychiatric Hospital, he was always seen watching over the younger patients like a caring grandfather. So once the spotlight was turned on him in Episode 12, we were more than eager to find out why he was committed in the hospital in the first place.
It was easy to assume that he might have been a hitman in his younger years when Dr. Oh described Mr. Kan’s history; he was said to have “killed people in the past” which led to his trauma. It wasn’t until he was in the bus with Sang-Tae that his Post-Traumatic Stress Disorder (PTSD) was revealed and triggered due to the sound of a jackhammer resembling gunshots.
It was such a painful scene to watch, from when his military dog tag appeared from under his shirt to when the entire bus shifted into a battlefield. We never expected it to take such a turn, especially for this very kind and gentle character. The next time this scene approaches during our re-watch, we’ll be more than prepared with boxes of tissue on our side.
The reason why Ko Mun-Yeong became a writer
We’ve always thought that Ko Mun-Yeong’s choice to become a writer was inspired by her mother, who was also a renowned novelist. They’ve often been compared both personally and professionally. This has even led to Mun-Yeong's father’s fear of her turning into a ‘monster’ like her mother. But in Episode 13, after her father’s passing, we finally got a glimpse of their father-daughter relationship before things got estranged.
Apparently, Ko Mun-Yeong’s fascination with fairytales was a result of one warm moment between the two of them, where he referred to her as the princess of their very own ‘castle in the middle of the woods’ while they were reading together. It was such a short and sweet yet memorable scene, especially in light of what happened early on in the episode, definitely proving that not all It’s Okay To Not Be Okay plot twists result in shock or heartbreak — well, sort of.