I know right! Roy is definitely the best (and only) choice for Ed! I could never see anyone else with Ed. Especially not his brother. xD Incest is disturbing.
Well, there's Marmalade Boy, but after 3 seasons the boy & girl end up with different people. It was a very well-told convoluted love pentacle.
Hunter x Hunter offers a platonic bromance, with Killua being on the obsessive side.
It's tough...I really can't think of any hetero ones & all the gay ones are short stories in single volume mangas. When it's a boy & a girl, the best friend always looses to the bad boy or if he gets the girl, they weren't really very close as friends.
I'm trying to think of one where they knew eachother as kids.
well,... me and my bestfriend before :-(
but she has a new one now :-) ....
oh....
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and my answer is honami(right) and adelicia(left) both in love with itsuki(middle)