In Gyeongseong Lady, Seoyeon’s role was Kasugayama Yuina—the primary antagonist operating on the surface.

Behind Yuina’s actions was Goto Isamu, who, ironically, appeared as an ally to the protagonist in the beginning.

The story began with this:
Kasugayama Yuina hired the protagonist, Yeon Sunye, for two primary tasks:

1. To locate the hidden assets of the Amanabi family and retrieve the keys to unlock them.
2. To eliminate Amanabi Michiko, the family’s sole heir.

"In return, you’ll receive enough money to live a life of luxury," Yuina said with a twisted smile. Her eyes narrowed, and her lips …