Based on the 2010 novel Princess Pyeonggang by film director and screenwriter Choi Sagyu,[5][6] it aired on KBS2 from February 15 to April 20, 2021, every Monday and Tuesday at 21:30 (KST).

[10] Originally, cast as On Dal, Ji Soo was replaced after allegations of bullying and sexual abuse sparked a scandal.

[12] The decision was also influenced by the positive reception to Na In-woo's acting and chemistry with female lead Kim So-hyun despite the circumstances of his casting.

[14] The series retells the love story between Princess Pyeonggang and On Dal, characters from a classic Goguryeo folktale.

Virginia Lim, Viu's chief content officer commented: "With an exceptional script and amazing talent, River Where the Moon Rises is not to be missed.

[46] Following the reports, a source from Son's agency MS Team Entertainment shared, "It's one of the projects she has received offers for, and nothing is decided yet."

"[47] The same day, it was also reported that Kang Ha-neul was cast as On Dal,[48] but turned down the offer due to a scheduling conflict on September 21.

[15] On October 13, it was reported that Ji Soo had received an offer for the role of Ondal, the male protagonist in the drama but was still reviewing it.

[51] On October 22, Ji Soo was confirmed to be acting as the male lead On Dal, with Lee Ji-hoon and Choi Yu-hwa joining the cast.

[8][53] The series reunited actors Kim So-hyun, Ji Soo and Hwang Young-hee who previously acted together in the drama Page Turner.

[55] On November 24, the extra's result was confirmed positive, but all affiliated cast and crew members tested negative.

[56] After the series ended, Lee Ji-hoon revealed he injured his nose during an action scene, suffering difficulty breathing.

[59] A poster released on January 14 features the silhouette of Pyeonggang on a horse with On Dal's face faintly hovering in the sky above her.

[60] The following is the official track list of River Where the Moon Rises Original Television Soundtrack album.

[109] Through a handwritten letter, Ji Soo admitted to the school bullying rumours and apologized to those who have been hurt by his past actions and those involved in the production of the currently ongoing drama.

[112] The following day, a KBS representative shared that filming scheduled for March 4 was cancelled due to Ji Soo's ongoing school violence controversy.

[116] Cast members Lee Ji-hoon, Wang Bit-na, Ki Eun-se [ko], Kim Hee-jung and Yoon Joo-man offered to participate in the re-shoots without payment.