Pure heart is the purest, it excludes selfish distractions, keeps away from the disputes of desires, and only accommodates the most beautiful and sincere feelings in the world, so "it can always embrace the pure heart of the world!" Chi's real life may be in a bad situation, lacking a bosom friend, and the world around him makes him very lonely; However, the purest and most beautiful feelings and thoughts of human beings are interlinked and eternal, and all sons in the world will become his bosom friends and friends. It is these spiritual friends and beautiful feelings that have become the vast spiritual world created by naked children.