"Remember your imaginary friend?" "Oh, Hokie? He never really left." Park Jimin had a normal childhood, living peacefully with his family, as well as his imaginary friend-- Jung Hoseok. They were absolutely inseparable, until the day that someone told Jimin that his best friend was nothing but a shadow. Years later, this so-called "shadow" reappears within the halls of his high school. Can Jimin really let himself believe again?