Gyejipjongeun Domangchinda

A young girl sold into servitude is given the name "Seo-hye" by Kwon Yoon, the noble son of a powerful family. Despite her lowly status, Seo-hye finds herself drawn to Yoon’s gentle nature, and he, too, begins to fill the void left by his parents’ untimely deaths with her presence. As their forbidden affection blossoms in secret, fate deals a cruel hand. The sudden announcement of Yoon’s arranged marriage shatters the fragile bond between them, setting in motion a tale of love, longing, and the inevitable heartache that shadows their lives.
(Source: Lezhin US)
Note: Chapter count includes a side story.