Ashita no Joe is a film that's very hard to evaluate or discuss outside of the context it emerged from. It's hard to call it a *good* film, exactly: it suffers from the kind of severe pacing issues you'd expect to emerge adapting a nearly 80 episode story into a single film, and at it's lowest points even the excellent designs can't really save the scenes that are simply underanimated and lacking in life. But viewing the film as someone intimately aware of the legacy of Ashita no Joe, it's hard not to instinctively look past the problems and appreciate the movie's best moments and core appeal. For every scene that drags on there's another that moves exactly the way you want it to and shows off the best of Dezaki Osamu's directing, and for all the barebones, underanimated moments within the film there are excellent bits of character animation and engaging fights that put the rough linework and overall aesthetic to great use.
Ultimately I think it is the protagonists and main characters in the film that keep it engaging even when it fails on a moment to moment level. Joe is likable and funny and kind of a jerk, and watching him grow bit by bit and find something meaningful to channel his anger and malaise into is satisfying. He has this roguish charm to him that's just flat out fun even when you're kind of bored and the movie is starting to drag, and despite his cruelty the tiny details in the animation when present make him feel like more than just an asshole and show you a level of interiority and complexity that keeps you rooting for him. The other characters are really solid, too, but the rapid arc of the show leaves moments that should be more dramatic (particularly regarding Tange) out of place and rushed. Still Rikiishi is compelling too, so you're genuinely invested in both sides of the final fight, which make the events of the ending (which I won't spoil if you happen to not know) feel impactful and satisfying.
That's again not to say the movie manages to overcome the structural and pacing problems inherent to it: it tries to adapt a very long story into a movie: a very long movie, but still just a movie. In some ways the length only makes it harder: it manages to slow down enough to be comprehensible, but I think if the fat was trimmed and the story was adjusted a bit those 2 and a half hours or so could be slimmed into a probably better film.
Still, Ashita no Joe is I think worth watching: for historical reasons, yes, but also because there's real value in the animation and characters on display here, and because the story has things to say and stories to tell that have impact and meaning today.
