Cook is one of Uwabaki (school shoes) for left foot and has a brother who happened to drop himself into a trash can. Cook then was thrown as well. In order to find his missing brother, he starts his adventure.
Although Cook seems timid, his strong sense of justice makes him always want to help someone in trouble.
Cook is sometimes lacks of confidence of himself when travelling alone. However, making friends with "things" such as books, glasses and chairs that he met in his journey makes him become stronger.