From this world to the next, 4 Kokdus accompany the dead to find the eternal peace. 

Brother and sister, Soo-min and Dong-min sell their grandmother’s shoes in a junk shop to buy a puppy. On the day they bring a puppy home, grandmother falls sick. Feeling guilty they head to find her shoes back. While searching the shoes in the pile of junk, they get lost and are sent to the underworld by mistake. There they meet Kokdus, the guardians to console and lead the dead to the underworld. With the help of Kokdus, two children set off the journey to find their grandmother’s shoes.