Ji-woo and Ji-yeon enter the studio of their father, who works as a painter, and become curious as they discover a book of Greek Roman mythology on a desk. Ji-woo and Ji-yeon hear the story of Greek Roman mythology from their father, and the animation starts with the stories of the Olympus gods. Cronus fears that his sons will be deprived of their status, and swallows them as soon as they are born. However, Cronos' wife, Rhea, did not want her youngest son, Zeus, to be stolen by her cruel husband, Cronus, so he secretly swallows stones and Zeus the baby escapes to a safe place for the maid.