The First Night with the Duke

Top Cast

Seohyun as Cha Seon-chaek / K
Ok Taec-yeon as Prince Kyungsung / Lee Beon
Kwon Han-sol as Cho Eun-ae
Seo Bum-june as Jeong Su-gyeom
Ji Hye-won as Do Hwa-seon
Lee Tae-seon as Prince Seonghyeon
Seo Hyun-chul as Cha Ho-yeol
Yun Yoo-sun as Yoon Deok-jeong
Lee Sang-un as Cha Jang-ho
Kim Shin-bi as Cha Du-ho

Seasons

Season 1 (2025)

University student, K, is an ordinary young woman who one day finds herself in her favorite romance novel set during historical times. She has now become the minor character Cha Sun-Chaek, the daughter of a wealthy noble family, whose dream is to have a peaceful and normal life. Cha Sun-Chaek, while possessed by K, then spends one night with Yi Beon, the novel's lead male character, who comes from a royal lineage and is favored by the King. He is cold-blooded, gifted with an attractive appearance and outstanding martial arts skills. Somehow, Yi Beon and Cha Sun-Chaek happen to meet and talk, and he is consoled by her about his heartbreaking past. They spend the night together. Soon, Cha Sun-Chaek tries to connect Yi Beon to Jo Eun-Ae, who is supposed to be the lead female character in the novel.

Episodes:

Ep. 1: Reading a Book is Inviting Another's Life into Yours (2025-06-11)

K finds herself inhabiting the body of Cha Sun Chaek, a wealthy but completely irrelevant side character. With a VVIP ticket to watch the epic romance unfold, her simple plan is to stay out of the way and enjoy the show. But that plan is spectacularly derailed after a wild night of celebration ends with her accidentally stealing the male lead’s first night.
Ep. 2: The First Night in This Lifetime (2025-06-12)

Cha Sun Chaek tried her best to run from Yi Beon.
Ep. 3: Something Always Happens on a Moonlit Night (2025-06-18)

Yi Beon encountered an unusual figure. Cha Sun Chaek tries to fix the story she broke. Jeong Su Gyeom held a gathering for the Astral Philosophy Club.
Ep. 4: We Need a Backup Plan (2025-06-19)

Yi Beon's persistence reached Cha Sun Chaek's family. Cha Sun Chaek encountered a foreigner. Do Hwa Sun persuaded the Queen Dowager to do something in her favor.
Ep. 5: There is No Such Thing as "As It Was" (2025-06-25)

The Palace officially hold the bride selection process for Yi Beon.
Ep. 6: Playing the Field and a Disguise (2025-06-26)

Yi Beon continues investigating the figures surrounding Cha Sun Chaek's incident. Jeong Su Gyeom gets jealous. Cha Sun Chaek made it to the final round of selection.
Ep. 7: The Inflection Point (2025-07-02)

Yi Beon and Cha Sun Chaek are getting closer. Jeong Su Gyeom braves himself to pursue his dream woman. A new villain entered the story.
Ep. 8: The Shadow that has Returned (2025-07-03)

Someone from Cha Sun Chaek's childhood past emerged. Yi Beon and Cha Sun Chaek's courtship faces another obstacle. Yi Beon's relationship with the King is being tested with the return of the exiled prince.
Ep. 9: The Wounded Things (2025-07-09)

Cha Sun Chaek and Yi Beon's courtship gained blessings, but the hardships remain. A highly unlikely pair starts to join forces.
Ep. 10: Once Again, Because of Fate (2025-07-10)

Jeong Su Gyeom obtained the truth. Yi Beon received punishment from the King. The Black Gang is getting stronger.
Ep. 11: A Dream or an End? (2025-07-16)

Yi Beon fights for his life, and his lover. Lee Kyu's plan fell into place. Cha Sun Chaek take matters into her own hands.
Ep. 12: Into the New World (2025-07-17)

Yi Beon and Cha Sun Chaek overcome their adversaries.