I dare say this was a great end to a great revenge manga. And no, I'm not gonna be one of those people who will decry other revenge manga that fall short of this one, because I think it's a dead horse that has been beaten long enough. All in all, satisfying results for what happened.
Mashima took his own life (good riddance), Nishida laments on forever being barred from achieving her dream (despite setting herself up for failure), Yumeka is just straight up gone with the heavy implication that her spiral downward will only continue, and Kurokawa's trapped in his own hell with (hopefully) no chance of parole. Really, Izuka is the one who managed to get himself out of the hole and his life together, and I couldn't be more proud of him. As for Sakurai... well, look at her. There aren't enough words to express how happy I am for her.
It's said that revenge is a dish best served cold, and by God, this dish was served at the absolute lowest temperature. And it hits regardless. My deepest gratitude to the author and artist of the manga, and and even bigger thanks to the ones translating it.