I am looking for manga that have teens or younger, that have married young because of love or family matters, or that they are engaged to married, but they interact in each other lives( or live with each other)
Since you are already reading the titles I thought of, Maybe you could try P to JK . The girl is a high-schooler though the guy is a bit older. Just like Faster Than a Kiss. These are both light and fun reads. Dear Mine kinda fits your criteria. The protagonists here are children in an arranged marriage.