Yeah I've read that spoiler and sure is like one of Seo Koji's shit walk of a manga. Seo's fans will say otherwise. At least in his manga, there's a "good ending" in it. Or any reader of this manga, they'll say, "Seo's ending is better than this". Maybe. Probably. What gets me the most in Seo's manga is his how he develops his plots. It's a walking disaster of a train wreck and ends it bitter sweetly. No, you can't justify Seo's manga endings with that kind of ending. It's still crap at the end.
The problem came with this manga once Kobayakawa chose Hoshino to be his girlfriend. Sure, Hoshino is the titular character but that doesn't justify as to how and why would Kobayakawa would fall in love with her. Is it because of how she lives her life or the decision she takes for herself? She couldn't even show her true face to her friends and even true to herself. Hachiman would like to have a word with you Kobayakawa.
The author crumbles his own manga at that point. At the very least, if he could've chosen Kanou, he wouldn't have this kind of shitty development where he needs to be secretive of his own relationship. It sucks to have that kind of relationship. It's like she herself isn't proud of their relationship. With Kanou, he wouldn't have that kind of situation. She herself will bark down at anyone questioning their relationship and she couldn't care less to anyone what it would look like to others about their relationship.
This is like Ichigo 100% all over again except for the secret relationship and whatnot. Damn I love that manga for it's bitter sweet moments and that ending. Couldn't predict the author would do that.