Welcome to the intense and fast-paced world of Seulro High School's hospital, where a new class of ambitious medical residents is about to learn that the real textbook of medicine is written in experience, not just ink. Resident Playbook follows the journey of three bright but very different interns: the driven and secretly burdened Cha Eun-woo (Go Youn-jung), the sharp-witted and fiercely independent Bae Soo-ji (Shin Si-ah), and the empathetic but sometimes uncertain Oh Min-chae (Han Ye-ji). Thrown headfirst into the demanding realities of patient care, these young doctors must navigate grueling hours, life-or-death decisions, and the complex hierarchies of the hospital. They'll forge unexpected bonds of friendship and rivalry as they learn to lean on each other for support, celebrate small victories, and confront heartbreaking losses.