When I was 17 years old
Song Wanmin, whose father cheated and her parents divorced, met Bai Yanzhou in Songgao
Both of them fell in love with each other as time passed
"Xiao Min, we have agreed that we will go to see the sea in the future and I will marry you."
"Yes! We have agreed to go see the sea in the future and I will marry you."
Concept: It's not that you are not the protagonist, it's that you haven't met him/her yet