What did Shen Jiayi whisper?

Shen Jiayi, the heroine of Giddens Ko's The Girl We Chased Together in Those Years, is played by Taiwan Province actress Michelle Chen. Shen Jiayi's prototype is the girl that Giddens Ko chased with others when she was young, and the film and works themselves are Shen Jiayi, a girl who remembers her youth and has been with her.