"If you have lingering attachments to this world, you can't rest in peace even after death. Knowing this, Sang-joo Kim uses his gift to see ghosts to help the deceased let go of their attachments and rest in peace as a soul guide. He also acts as a substitute chief mourner for unclaimed deceased individuals in public funerals. Sang-joo Kim tries to help Hyun-woo Nam, a high school senior for whom he acted as a substitute chief mourner, rest in peace. Under the condition that one must express their honest feelings verbally to let go of attachments and rest in peace, Hyun-woo can't achieve it because, unlike others, he doesn't even know what his attachment is. Opposite to Hyun-woo is Ji-woo Lee, Sang-joo's first love and long-time shadow. Even after death, Ji-woo lingers around Sang-joo, wanting to remain his one and only love. The intertwined story of Sang-joo Kim, the substitute chief mourner, and the two ghosts who can't rest in peace, Ji-woo Lee and Hyun-woo Nam."