Karen Aramis, a young woman with brown hair and piercing grey eyes, battles Tetralogy of Fallot—a severe congenital heart defect marked by four structural abnormalities. Her critical condition, deemed nearly insurmountable, captures the interest of Kuroo Hazama, an unlicensed surgeon notorious for navigating high-risk medical cases.

Born into a family entangled with organized crime, Karen’s lineage ties her to Patterson, her crime-boss grandfather. Desperate to save her daughter, Karen’s mother, Saranda Aramis, brokers an alliance with Hazama, propelling the surgeon into a war-torn region ravaged by civil conflict. The life-or-death procedure unfolds in a makeshift field hospital, its scarce resources stretched thin, with volunteer medic Catherine aiding Hazama amid chaos.

Karen’s plight ignites tensions within the International Medical Association, framing her surgery as a flashpoint for debates over ethical boundaries and healthcare inequity. While her story orbits these systemic struggles, her familial bonds—particularly with Saranda—anchor the personal stakes of her harrowing fight for survival.