I'm looking for a boy who's the pinnacle of "nice guy", to the point of being almost or completely a pushover. The sort of guy who always thinks of other people before himself, to the point that he stands the strong risk of losing out on a lot of things unless someone either knocks some sense into him or cares enough to make sure he gets a share of the happiness. Bonus if romance is involved and the story is complete.

One great example, character-wise, is Takeo from Ore Monogatari. This guy is caught on several occasions implying that he wouldn't even mind if his girlfriend cheated and/or dumped him if the other guy would make her happy, and initially he tries to set her up with his friend because he's too dumb to realize just how crazy she is for him.
I'd like to see a story that stretches things a bit before the payoff compared to this though, something where I have to read through at least a couple volumes to see the guy find happiness. That said, nothing too long. I don't want to have to read several years' worth of material to get to the payoff. If you have a really touching one-shot, I will accept that as well, I just prefer something a bit thicker.