When Song Xia was Su Jin's brother, he liked her.
Song Xia became Su Jin's boyfriend. He liked her.
Song Xia became an indispensable and important role in her life. He liked her,
Song Xia died, she degenerated into an ugly duckling, and he liked her.
He didn't know where this love started, where it ended, and whether it would be satisfactory or not. He never cared about these things.
15 Years of secret love, in the end, it just turned into one sentence: Marry me, girl.
I promise you a lifetime, but you don't know how many years I have loved you.