Bom Center, a non-profit care center for abandoned dog. Choi featured in the September issue of Star1 Magazine for his first solo interview and photoshoot the same year, and competed in the Idol Star Dog Championships, a dog agility competition, which aired as a Chuseok special on MBC on 2 October. On 25 September 2020, he was cast in Netflix's new sitcom So Not Worth It, which tells the stories of a group of multicultural students living in a college dorm. The series became available on 18 June 2021, and he sang the homonymous OST for it. With his portrayal of Sam, the son of the CEO of a food chain based in Australia, he drew attention, and was praised for his acting, communication skills, vocalization and pronunciation, which, along with Choi's facial expressions, realistically expressed the character's emotions. 2021–present: Departure from JYPE, Midnight Sun and solo debut Following the expiration of his contract with JYP Entertainment, he signed an exclusive contract with Sublime Artist Agency on 20 January 2021. On 9 March 2021, it was announced that Choi had joined the cast of Midnight Sun, a musical adaptation of Japanese movie A Song to the Sun, in the leading role of Ha-ram. Midnight Sun was performed from 1 May until 25 July at the Kwanglim Arts Center. He starred in 22 out of 95 shows. Two of the songs, "Meet Me When the Sun Goes Down" and "Good-bye Days", were also released as singles by each main actor: Choi's version of "Meet Me When the Sun Goes Down" was released on 9 April as part 1 of the musical's soundtrack, while his collaboration with Lovelyz' Kei on "Good-bye Days", on 7 June. On 1 April, it was confirmed that Choi was selected as campaign artist for Levi's Red alongside Lim Na-young. On 20 April, he took part in Levi's 501® Day Music Concert, where he performed self-written song "Lonely", Sole's "Ride" and Christopher's "Bad". On 7 May, he released the soundtrack "Pop Star" for the web series So I Married the Anti-fan. On 5 October, he made his solo debut with his first extended play, Colors from Ars, and its title track "Vibin". Six days later, he released a fall-winter clothes collection in collaboration with Korean casual brand Plac. He then performed at K-pop cheering concert, We All Are One 2021 to overcome COVID-19 on 31 October. In November,