But it does still feels kinda unfinished. MC's sudden comeback in the fight feels like a wonder, that was necessary for a happy end, and there really are still many subplots untouched. Also the main couple's relationship progressed smoothly, slowly but steady (which made this story so great), it really doesn't feel at the end of this plots journey. The series has a feel to it like it has been planed out to last at least another 30-40 chapters (if it isn't even just halfway finished).
@frubam beat me to it, but I also thought that image of him falling would be how it would have played out, if the manga would have continued and that the author wanted to show just that. The inbound media drama and the messing of the principal and mayor would also have made for a decent drama with a fine closure and heaps of justice in the end. MC failing as a boxer, but ruling as a coach. A bit of heartbreak for the side girls. A bit of development for the side characters.
But, well. It's not unthinkable, that he withstood those blows and that his rival is weak to hits. The image of MC falling, but then still standing in the end, is also a nice way of fooling the readers and increasing the tension. Fucking up the principle and major's drama by just jumping in might also happen this way in RL (And wasn't that just glorious 😆?). The side girls being left in the rain also feels rather RL if you think about it. Unrequited love. Too bad.
All in all, not that unrealistic for an ending. It feels rushed from a storytelling standpoint, but hey. And another 4 chapters for a decent ending? That's not too shabby. There are other mangas, that blow such a window and still felt rushed. Let's see how this mangaka handles it.
But to really express my feeling: NOOOOOO! Not another tomboy manga axed!