Let me just say that I'm a fan of boxing... but that's not why I liked this anime. In fact, I suspect that some boxing fans will absolutely hate it, due to the unrealistic, and frankly childish portrayal of the sport. It'd be for the best though, to forget that this show is about boxing altogether. Just let your mind submerge into the brilliant (even if over-the-top) characters, into the light humor, into the flaming feelings and emotions.
Boxing does take up a large portion of the plot, so if boxing or violence is REALLY not your thing (and I mean REALLLLLLLLY), then you might want to abstain from watching it. Otherwise, it's a great watch.