A young Japanese boy finds himself stranded in Manchuria after his nation's collapse in 1945. Unable to return home, Megumi Sunahara drifts through occupied territories doing whatever work keeps him alive, herding cattle on rural estates while Japan fades into memory. Everything shifts in 1948 when he makes an impossible choice: abandon his identity and join the People's Liberation Army under a Chinese name. What begins as survival becomes something deeper as Megumi commits to a revolution that has nothing to do with his birthplace and everything to do with the person he's becoming. Across brutal campaigns and pivotal battles, he witnesses history from an angle few outsiders ever see, fighting alongside soldiers who know nothing of his true origins. The series traces how a displaced teenager transforms into a dedicated revolutionary, caught between two nations and loyal to neither. Blood and Heart examines what happens when circumstance strips away nationality and ideology becomes the only home a person has left. This is the untold story of a man who chose a new country over the one that abandoned him.