Character Arc
Um Jae-il is one of the four first-year obstetrics and gynecology residents at Jongno Yulje Medical Center in Resident Playbook, rounding out the core cohort whose shared trials anchor the series. As a newcomer to the punishing rhythms of the OB-GYN ward, he experiences the same steep learning curve as his peers, navigating long overnight calls, demanding seniors, and the emotional swings of a department where outcomes can change in an instant.
Through the season Jae-il grows alongside Oh Yi-young, Pyo Nam-kyung, and the rest of the first-years, contributing to the warm, comedic, and occasionally tense camaraderie that defines the group. His presence helps the show explore the everyday texture of residency, from the small humiliations of being the most junior doctors in the room to the hard-won satisfaction of getting something right under pressure.
As part of the ensemble, Jae-il's development is woven into the larger story of strangers becoming a found family, reflecting the franchise's signature focus on humane, character-driven storytelling. Because Resident Playbook is a recent release, the specific details of his background and arc should be verified against official sources.