Seoul 1945 is a drama that takes place during turbulent times in Korea, spanning from the end of the Japanese occupation to the eventual split of the country into North and South. The story revolves around the lives of four young adults who grew up together. Choi Oon Hyuk (Ryu Soo Young) is a child prodigy born into a family of poor miners; Kim Hae Kyung (Han Eun Jung) is the eldest daughter of tenant farmers; Lee Dong-Woo (Kim Ho Jin) is the heir to a wealthy, well-connected family; and Moon Suk Kyung (So Yoo Jin) is the only child of an affluent and powerful political ally of Japan. In a blend of personal choices and circumstances beyond their control, each individual embarks on different paths that reflect the chaotic nature of the time as well as their true character. As their paths collide, love, friendship, loyalty, vengeance, moral conscience, and ideology become driving forces to irrevocably change the course of their lives.