Kannazuki no Miko is widely known as a yuri series, but it’s also been described as a bisexual love triangle. So the most important male character, Souma Oogami, tends to get some hate from some of those who watched the series only for the yuri.
(This post will contain spoilers for most of the series.)
I think this is undeserved, for several reasons, but let’s just start with this. We are talking about a series in which a character who had to choose between two love interests of different sexes chose the one of the same sex, and it wasn’t because there was anything wrong with the opposite sex option or because she suddenly realized she was only into girls. How many times does that happen?
I don’t think Souma’s good qualities not related to the triangle situation really need much defending. He’s hotblooded, decisive in the midst of angst, and a rare (in anime) illustration of how the personality of “the hero” adapts into a supporting role.
Souma is sometimes considered an example of the “male interference” yuri trope, but he’s hardly a textbook case of it. For starters, he doesn’t know he’s interfering with anything; he may or may not be aware of Chikane’s feelings for Himeko, but he definitely hasn’t seen any indication that Himeko might be romantically interested in Chikane at any point before the last real romantic interaction between him and Himeko. (And the margin isn’t even a small one if you don’t count things like the fact that the manga he buys for Himeko is a yuri one. Incidentally it’s also by Reiko, and Himeko being one of her fans is arguably the greatest relevance Reiko even has. (I swear I don’t hate Reiko or anything.))
The fact that Himeko doesn’t give up on Chikane when she’s an apparent enemy and even after what Chikane did has been widely observed, with varying reactions. The fact that, after Souma’s initial reaction, he commits himself to helping Himeko talk to Chikane, as opposed to trying to convince Himeko that Chikane really is an enemy, is often overlooked.
And then, when Himeko does make it clear that Chikane is the one she really loves, Souma accepts it with more grace than nearly anyone of any gender and orientation would in a similar situation, and says he has no regrets. Souma is a guy who’s genuinely nice, not a “Nice Guy” who only does things for a girl because he wants something in return.
In fact, that’s a parallel between Souma and a certain character who is popular with yuri fans; Tomoyo from Card Captor Sakura, who would rather see the girl she likes happy with a boy than not happy. (Though in that case, Sakura never did even realize that Tomoyo likes her at all.)
This is also one reason why Tsubasa is so important. Souma gets his brother back and therefore has a happy ending anyway, and I think this may have been done on purpose so we can like him without feeling any temptation to feel “sorry” for him because he “lost” Himeko.
(Actually giving him an alternative love interest wouldn’t have really worked; if there’d been any indications earlier than the last episode his acceptance of Himeko choosing Chikane over him would seem more shallow, and if there hadn’t it would just be too last-minute; and there wouldn’t have been a good chance to give any real characterization or development to the relationship either way.)