I honestly hated this work. And I think my issues are similar so others I've read, but I also have a different perspective on them.
What this comes down to is it reads like the author got bullied by their publisher.
In the beginning, it is made pretty obvious that Tai is in love with Touma. Like, OBVIOUS. Sure he is also envious of Touma, but that's in addition to his love. The rest of my comments are heavily spoilers but I recommend reading them before reading the series anyway.
So as I was saying. It's obvious. He doesn't like Futaba because she is meek and reminds him of himself. He loves Touma but is envious of all that Touma has.
But then you hit a chapter where it seems like the publisher came to the author and said "Look, we can't have a gay romance story, it won't run long."
At which point, suddenly we get reference to Tai actually almost hating Touma and suddenly loving Futaba. It's a complete 180 and it comes out of nowhere.
Futaba herself is a horrible character. Not because she's meek or clumsy or a typical shoujo heroine trope, but because SHE DOESNT LOVE EITHER OF THEM.
We're basically told to believe she loves Tai, but that's not what happened. She admires Touma and she's friends with Tai. For some reason she decides she needs to be romantic with one of them, and forces herself to choose one to date, and decides she'd rather date Tai.
There's no love there. He has equal standing in her eyes as her friend (whose name I can't even remember but it begins with M so I'll call her that) which is shown with the whole university plotline.
Yet she doesn't want to lose his love so when shit hits the fan she decides to stay with him. Even that wasn't because she liked him too much to give him up, it's because Touma told her to stay with Tai.
The argument with Touma's friends and the whole discussion that takes place in their room is sickening as well. Yes, there are two sides to a story, but trying to justify an assault due to bigotry is ridiculous. I've been assaulted a lot in my life and I've never once decided that all men are like that and disgusting. You can't say that's a justifiable stance to take ESPECIALLY when you're supposed to be close friends with the person.
By the time we get to the ending, I wanted to erase this whole manga from my memory.
Even though it's labelled shounen ai, by the end all non hetero relationships have been completely erased from the work.
M states early on that she tries to be normal and date men but she can't make it work, she only likes women. But by the end she is somehow doing well and is married to a man.
Despite making the Touma character be the only one to truly show love throughout the series, we not only get deprived of seeing him in the ending, we don't even really get to see his happiness AT ALL.
We get a picture of two wedded hands holding each other. Ok great. They got married. Touma gets no lines, no kiss, no acknowledgement. Just a held hand.
This after we're told he had to put up with the 1 year shown, the 2 years Tai and Futaba dated afterwards, and the 5 years of Tau "not being over Futaba". AT LEAST 8 YEARS he had to watch Tai pine over Futaba when neither actually loved each other.
Not only that but the author dared to write a line like "it was obvious Tai liked you from the start". What? No! Tai was uninterested, malicious, and pushing Futaba toward Touma while obviously loving Touma at the start. GRAAAAH.
Its a classic example of a writing just writing "yes x loves y" instead of showing it with any actions or gestures or anything meaningful. It was a complete waste of time reading this.
Honestly, it is NOT a shounen ai. Its not even suppostive of the LGBTQA+ community. It doesn't depict them "struggling with their identity" but rather erases Tai's and M's and punishes Touma's.
It was extremely disappointing and a huge waste of time to read.