As an obsessive reader, I very rarely express the feeling I'm about to, but that's what Food Wars has brought me to – I wish it hadn't stuck so close to the books. While this final season hasn't been Food Wars at its best in general, the reveal that Asahi is really Azami's son and therefore Erina's older half-brother just brings in an unnecessary element of near-miss incest that the series really didn't need. Although, it does solidify the idea of Azami as a tool, not because he had a son before he married Mana, but because he abandoned him. (That Azami does not deserve the level of forgiveness he gets is an entirely different issue.) That means that if things had gone just a little bit differently, Erina and her brother would have been a couple, and not only is that sort of thing well outside of Food Wars' wheelhouse, it also directly undermines the plot. Had Asahi never attempted to marry Erina but instead been solely consumed with belonging somewhere, the ending wherein he finds his family would have been kind of sweet, because unlike Azami, we can see where Asahi's issues stem directly from his lack-of-a-family situation. As it stands, there'll always be that awkwardness, although I'm not sure if it's really any worse than Erina accepting her abusive parents back into her life. I understand that the story was going for a happy ending, but seeing Erina willingly ignore all of the horrors both Azami and Mana inflicted upon her just doesn't sit right with me.
Similarly, this finale sees Soma being more than a little out of character. One of his defining features, particularly amongst his Totsuki peers, is his ability to take losses in stride and to learn from his failures. This has held true even when he's known the contest was rigged, so it doesn't make a whole lot of sense for him to be so upset that he lost the Blue, especially given that his dish was less designed to make Erina say it was delicious and more to force her to seriously devote her skills to the competition. He's savvy enough to know that the win would mean much more to her, so his pouting and then taking off on a training journey just doesn't feel like the sort of behavior the character we've been following for five seasons would engage in. (The squid thing, on the other hand, absolutely does, although I could have lived without the return of the tentacles.) What Soma shows in the final quarter of the episode isn't character growth or development – it's fairly random behavior, especially since previous to the exact moment he says it he's never doubted his ability to take over the diner.
I wish that I could be more surprised that the episode was so off, but this season of Food Wars has consistently been devoid of all of the things that made the earlier ones so good. We don't even see Erina make her dish or her mother taste it (although since tasting Soma's made the building disrobe, I'm not sure how they could have topped it), which is not only a let-down but also a tacit admission that maybe Soma's was the better dish and Mana awarded Erina the prize because she's her daughter, rather like how no one in Noir is ultimately punished because of Poor Sad Abandoned Asahi. (In fact, they all appear to be working for the Nakiri family now. No, that's not suspicious at all!) And as long as I'm being cranky here, the sudden shoving of a romantic subplot into the final moments of the show is very much too little, too late. Not that Soma seems to reciprocate Erina's feelings, despite what Mana implies, but Erina's sudden decision that she's in love with him feels at least a little out of left field and serves no purpose other than to have Soma get the girl in the end, whether he wants her or not.
At the end of the day, Food Wars was a show that didn't know how to handle its own finale. It tried really hard, but eleventh hour reveals and a lack of focus on cooking and food in general dragged it down, leaving it a shadow of the story it started out as. It's sad to see it squander its potential, but here we are.
So long, Food Wars. If you ever get a remake, I hope you're able to address your problems.