I don't know what to say, so here is an outline of what happened in a novel I am writing now,
My MC is a black slate after an accident and does not have much to do with his past, but his sadness or drive comes from the fact that his GF gets to be with him for a literally few days before to be married off with a wealthy noble. To avoid any bad news in the future, everyone around MC who knows him tells him to make do with life, and he also gets to marry a girl who loves him.
But now the MC miss those few days with his GF and slowly starts to trace back the leads to his GF with his wife, who is ready for a possible harem.
Yet there is non till now.