那个季节我们发誓那个夏天我们承诺
[nèi gè jì jié wŏ men fā shì nèi gè xià tiān wŏ men chéng nuò]
'Na Ge Ji Jie Wo Men Fa Shi Na Ge Xia Tian Wo Men Cheng Nu' translates to 'That Season We Made Vows; That Summer We Made Promises.' This conveys a reminiscence for past promises and oaths during specific times in one's life. Often, it can carry nostalgia about missed or broken vows/promises, indicating that the user may have experienced some regrets over past relationships and decisions.