Reception
On the review aggregator website Rotten Tomatoes, 83% of 6 critics' reviews are positive, with an average rating of 6.2/10.
Lee Min-ji of Newsen felt that "what stands out the most in this drama is the complexity of Lee Doo-na's character", describing her as "eccentric and outspoken, but also with a dark side", and appreciated Suzy's acting, who "played her complex sides with stability". Jeong Seung-min of MHN Sports appreciated how Suzy expressed the change that occurred in Doo-na after opening her heart to Won-jun and the chemistry between the lead actors, but also wrote that the series "can be childish" and "feels like a typical youth drama or a web drama depicting campus life". Choi Ha-na of TVDaily criticized the drama, stating that it has a predictable plot as it only focuses on the romance between Doo-na and Won-jun (while in the webtoon he is torn between her, I-ra, and Jin-joo) and the supporting characters have no function other than that of "bridesmaids" to the leads. However, she praised Suzy's acting, who "played every moment of Doo-na with just the right amount of intensity, never overdoing it or disappointing", considering it a good enough reason to watch the series. Journalist Kim Jun-mo of OhmyNews called it "boring" as "other than Suzy, the show lacks any memorable parts".
Joel Keller of Decider wrote that "Doona! is a pretty standard romantic K-drama in a lot of ways, but the added dynamic of a regular guy and a depressed K-pop star falling for each other makes things just a little more interesting". Joanne Soh gave the show 3 out of 5 stars in her review for The Straits Times, identifying Doo-na and Won-jun's chemistry, the cinematography, and the show's treatment of the protagonist's mental health issues as the show's strengths, but found it to be "oddly slow-moving" compared to the webtoon. For Geoffrey Bunting of Rolling Stone, Doona! "[weaves] a complicated yet relatable narrative about loss and love. On the surface, it feels at home with contemporary clichéd dramas yet represents a startling departure." He appreciated how it "builds a community around Lee Doo-na to pull her out of isolation and help her rediscover herself", and called it "a show that's really about letting go — shedding old lives, past loves, and former selves" that "deftly navigates the complexities of grief and, though wrapped in K-drama clichés, is surprisingly human". The series hit the No. 1 spot on Netflix's top 10 TV programs in Singapore.
