Juiz

Juiz (ジュイス, Juiz) is the head of Yulryeo's Intelligence Service and acts as the assistant of Yeomra during international matters. "Juiz" is a codename she though of when she assumed her position, her real name only being known to her and Yeomra. Despite having little combat presence, she is considered one of Magoseong's most powerful assets and her analytic ability has provided the backbone for most of its recent achievements, including its treaty with Iwagakure

Childhood
Though it is known to no one but the two of them, Juiz and Yeomra were actually childhood friends. Juiz came from a lower-class family within the capital and even as a kid showed remarkable intelligence and creativity, which she then used to infiltrate the homes of the rich and steal their valuables. One day, she even managed to reach as far as the heart of the palace, where Yeomra was kept hidden, without alarming anyone else of her presence. Stumbling into his room by accident, the two took a liking to each other and she started to visit his quarters regularly, never getting noticed. For the both of them, it was the first time meeting someone of their age whom they could speak with on their level of reasoning.

This ritual persisted as they grew up, and it was Juiz who eventually pointed the paradox of Yeomra's situation that led to him seizing the throne: Because of the tradition of hiding away the heir to prevent them from usurping the throne, a situation was created where Yeomra became the least suspected person to start a coup. From there on, they crafted a plan which succeeded, granting Yeomra the throne and Juiz a position as his right-hand.