Everyone who's saying that this series is getting milked is crazy. If this manga ended at that wedding chapter I'd be genuinely pissed at such an weak sauce ending for a series which has been relatively great overall.
The main problems would be the last volume being too cheesy and honestly cringe due to the fighting scenes being prolonged AND the art style when drawing them lacking... Finesse? It was just plain to see that the artist couldn't draw good looking fight scenes.
Then you add it with chapters being too short/not having enough substance, it just doesn't make for a good look.
BUT even with all of that! Ending the series with such an casual, lame, trash ending like this would had been horrible! The only true ending for this series is when the MC FINALLY does what he declared he was going to do! And that's becoming the Boss of all delinquents. That's the only ending worth settling for