First off, I don't remember if it was a oneshot or a series.
There's a guy who is part of a gym (he does boxing) and he's in a relationship with the gym owner's daughter. He's supposedly really good, but he gets seriously injured in one of the matches, and the girl finds herself wanting him to lose his matches so that he'll quit boxing and stop getting hurt.
I'm not too sure about the girl, but I think she was aiming to be an actress.
The two of them have a talk and the guy says that his boxing career is more or important (or something along those lines) and they break up. A few years later, he sees a poster of the girl starring in a show.