He met her during an outing, and she had just begun to fall in love with her. He treated her like a sister at first, but I don't know when their relationship started to change.
He was leaving, and his promise to her was to marry her when he came, but he broke the promise and she went crazy.
Because her mother is no longer here, and so is her lover.
From then on, there was always a long-haired girl in a white dress at the airport gate of City C. She waited there for a long time, and no one knew where she went.
Concept: Happiness and accidents, you can never know who comes faster than who.