While working in a hospital, he meets a famous children's book writer, Ko Moon-young, who is rumored to have antisocial personality disorder.

It's Okay to Not Be Okay was planned by Studio Dragon, written by Jo Yong, directed by Park Shin-woo, and produced by Story TV and Gold Medalist.

[14] In the second half of 2019, Kim Soo-hyun considered It's Okay to Not Be Okay to be his comeback drama following his obligatory military enlistment,[15] and his casting was confirmed by his agency in February 2020.

[5] In March 2020, veteran actor Oh Jung-se accepted the role of Moon Sang-tae;[6] when asked about his character at the press conference, he commented that "autism isn't an illness, but something you're born with".

[40] Smart Media Rep (SMR), which distributes VoD (video on demand) clips of major broadcasters to online platforms like Naver and YouTube, reported the drama had over 110 million cumulative views as of December 10, 2020.

[44] Following the popularity of the drama, the outfits worn by Seo Yea-ji garnered attention[45] and raised the profile of Korean fashion designers and brands of earrings, handbag and nightwear.

[48] It's Okay to Not Be Okay largely received positive critical feedback, primarily for its unique premise, visual storytelling, acting by the cast and importance given to mental health.

"[50] Contributors to Manila Bulletin considered it "unafraid to introduce fresh elements" with necessary clichés in a romantic K-drama, and praised Moon-young as a "headstrong" and "independent woman".

[51] However, when the series debuted, culture critic Chung Deok-hyun was concerned that Moon-young's "exaggerated words and actions" could decrease viewers' immersion in the drama.

[53] Rumaiysa M Rahman of Prothom Alo praised writing that "this drama makes people realise, societies should stop looking at those who seem different.

"[54] John Lui and Jan Lee of The Straits Times gave the drama a rating of 3.5/5 stars and said that Kim "pull[ed] off a sensitive portrayal of a young man whose life has been derailed by tragedy".

"[56][7] Edmund Lee from South China Morning Post gave a rating of 3/5 stars, pointing out that the series would disappoint "detective fiction fans" because of the limited explanation of mystery surrounding the murder.

"[58] The series was criticized on social media and the Korea Communications Standards Commission received over 50 formal complaints, largely for a scene in which Moon-young overtly stares and touches Gang-tae's body as he gets dressed.

[59] In another scene a male character, who suffers from manic depression and exhibitionism, reveals parts of his body, with his genitals being covered by a drawing of an elephant.

[63] The series was also one of the most popular Korean dramas of 2020 on Netflix in Australia, Hong Kong, India, Japan and South Africa.