Sansinbu

The 'Horang Sansinje' is the biggest (festival) held every 10 years in a shaman family. The Horang Sansinje, where human sacrifices have been practiced since ancient times, used to decorate a bridal chamber, or 'Sanshinbu's Room', to offer a fake bride to the Sansin and marry him off. 'Na-Ri' secretly enters the bridal chamber without the adults knowing and spends a night there. 10 years later... A man with a strange vibe appears in front of Na-Ri, who is very drunk, at a freshman welcome party.

(Source: Ridibooks, translated)

Note: Part of the 2024 Post Type Fall Anthology ([BL] 2024 포스타입 앤솔로지 | 가을).