A lot of sports anime and manga tend to focus on a team, a group of people all with their own individual stories that have a lot of weight. But Ashita no Joe isn't really like that. Joe is a boxer, which means the sport he competes in is an individual sport, and this is reflected in the series famous ending, where Joe dies. Every character in Ashita no Joe only has relevance in the way they directly to Joe himself. My favourite moment in the entire series is during Nishi's retirement party, however I don't really care all that much for Nishi on his own, the reason I love this part is because it features Joe asking Noriko if there's something at the party he can help out with, showcasing how he has changed throughout the series as a person. What could be seen as Nishi's final big moment, is great not because of Nishi, but because of Joe.
All of this is then reflected in the ending, where Joe dies. And when Joe dies, what happens? The series ends. Then, and there. Because the characters in the story have no relevance outside of how they relate to Joe. And this gets me to what I really want to touch on, which is that, it demonstrates how real life functions as well. I've been thinking a lot, about death, and what comes after, very unproductive, in fact, it is the most unproductive thing one could do and I'm trying not to, it's going well so far, I have faith in the immorality of the soul, end of story. But I'm getting off track, because regarding what comes after, you don't know until it happens. There's a chance its nothing. When I watch videos about climate change and what not, if this is really outside my lifetime, then it's not going to affect me, meaning if there is no afterlife, it might as well not happen at all. If my consciousness does not continue to exits past death, reality itself doesn't either. And in turn, the ending of Ashita no Joe embodies that concept.