Rekindling an old romance + a powerful man gradually letting down his defenses for love + childhood sweethearts + the heroine is the one and only moonlight in the hero's heart + a little angst first, then overwhelming sweetness
When Chen Weixi tries to mend their broken relationship, she discovers that Su Xunan, the fiancé who once adored her, has long since become indifferent. She can't accept it, but Su Xunan tells her they were doomed from the start, and even offers her a lesson in life: You can look back, but you can't go back, because anyone going the wrong way is fully responsible for the accident.
Just as Chen Weixi is learning to understand this philosophy and let go of their ill-fated romance, he says that a destined match may bring happiness, but a doomed romance is far more exciting. Later, he takes full responsibility for it.