In this futuristic world of 204X, everyone has the chance to freely choose their gender when they come of age. Yi An, a young person on the edge of seventeen, likes and prefers girly and feminine aesthetics. He feels that he isn't masculine enough, but he doesn't feel like a woman either. Yi An is in love with his classmate Zhou Yang Kai, but she expects him to become a girl. Yi An questions whether his attraction to Zhou Yang Kai is based on a gender preference or a connection of souls.