Childhood friends who have drifted apart
The childhood friends is a popular trope in all romance media, harem included. But my favorite sub trope within the trope is childhood friends who have drifted apart and reconnect during the story. Thus, I want some recommendations that have this premise.
This could happen for a variety of reasons. The MC and the love interests could fall into different social circles as they grow up. They both have careers that cause them to end up in different places. The LI could become famous/powerful and thus sees the MC less and less until they no longer have a relationship. Maybe there is a misunderstanding and their prior relationship ends on bad terms.
My favorite setup for this trope that I’ve seen in some books and anime is when the MC and LI are friends during their youth, but the LI is forced to leave the MC because she becomes famous/powerful while the MC is a commoner/unimportant. They both still want to be together, but society is the main force that keeps them apart.