They met when they were seven and promised to stay together forever. She transmigrated to another world and forgot him. He crossed between two worlds to stay by her side, watching as she mistook a vague silhouette for the object of her obsession. On her wedding day, she fled, and he smiled behind the scenes as he let her go.
If you remember me, then I have waited for the best possible ending. If you still don't remember me, then I'll wait again.