Synopsis: My Hyung's Sunbae

Injoon, who has returned from studying abroad, is devastated to learn that his former partner, Saein, has fallen for Jaekyung, who has a reputation for being promiscuous. While Saein walks away from Injoon to meet Jaekyung, she fails to notice a large truck heading towards her. Injoon and Jaekyung rush to her aid and all three are involved in a tragic accident. After being unconscious for a long time, Injoon finally regains consciousness and is astonished to discover that he is now inhabiting Jaekyung's body.