[2][3] Production company Shinswave announced Midnight Sun in early March 2021 by revealing the casting of Shinee's Onew, Day6's Wonpil, Got7's Youngjae and Cho Hun for the male lead role of Haram, Kang Hye-in, Lovelyz's Kei and Lee Ah-jin for the female lead role of Haena, and Kim Ju-ho and Jung Eui-uk as Haena's father.

[4][5] The musical debuted on May 1, 2021 at the BBHC Hall of Kwanglim Arts Center in Seoul, and ended on July 25,[1][6] with a limited number of people in the audience due to social distancing norms.

[12][13] In addition, Midnight Sun was live screened in South Korean cinemas on May 7 by CJ CGV in 29 theaters nationwide, as the tickets for the offline performance were sold out as soon as they went on sale.

[25] Seo Haena is a girl who has to avoid the sun due to a rare disease called xeroderma pigmentosum, therefore she's only active at night, when she's used to go busking at the train station with her guitar.

When they meet up, another street performer has occupied Haena's spot, so Haram takes her to a square, where a crowd gathers to hear her sing and play the guitar.

Their date ends abruptly as the sun breaks and Haena rushes back home: Haram is therefore informed of her condition and, although initially taken aback, starts reading medical books to better understand.

On June 26 and July 3, Kei couldn't perform due to self-quarantine after Lovelyz' Seo Ji-soo tested positive for COVID-19, and was replaced by Kang Hye-in.

[26][27] The performances initially scheduled for the evenings of July 18, 21 and 22 were cancelled due to new authorities guidelines about social distancing, which restricted gatherings of more than two people after 6 PM,[28] bringing the number of shows to 95.

[40][41] Midnight Sun was a box office success, selling out tickets during its run, and drawing favorable reviews from domestic as well as global audiences.

[18] Next Daily highlighted the faithful reproduction of the scenes from the original work, which were reinterpreted with a musical feeling, as the strength of the play, and stated that Haena and Haram's pursuit of the ordinary made people reflect on the new concept of normality brought about by the COVID-19 pandemic.

[48] For The Voice of the People, "The development and subject matter presented universal emotions such as the freshness of a first love, the affection and the sadness of a terminally ill patient, and a family member watching over them.