There are two friends like this who grew up together. Because they are both only children in the family and have no brothers or sisters, they regard each other as their own brothers. They poke honeycombs together, climb trees and steal bird eggs together, tease girls, practice piano together, grow up crookedly with schoolbags on their backs, and laugh proudly together. They have no secrets and wear mixed clothes and shoes. But one day, they fall in love with the same Cinderella, how should they choose?