Any manga where the male and female leads are close and the male lead is in love with the female lead? Well, he thinks she likes him back, but in reality she either likes or begins to date someone else and that causes the male/female lead's relationship to sour. She though might be unaware of his feelings and still tries to be friends with him not understanding why he pulls away. In the end though, she finds out his feelings and comes to terms with her own feelings and they get together.

I know it's a little specific, but it doesn't have to be exactly as I described. Just the main focus being male lead likes female lead while she likes someone else, but in the end the leads get together. Preferably the male lead remains single while dealing with this, but it's not mandatory.

Uwagaki sorta. The female lead is dating someone, but the male lead isn't really suffering and is...

sorta dating a copy of the female lead.