This is one of the rare moments when an anime movie is satisfying. I suspect that this might be because this movie is actually canon. Basically, a new villain (the first challenger) is introduced. I say "villain", but it's more like "likable rival". The plot is ridiculously predictable, but has enough of "Hajime no Ippo" charm, and humor to keep the audience going, regardless. Watch after "Hajime no Ippo" and before "New Cahllenger".