Good job on developing the two characters. They felt like friends before they became lovers and it felt very natural. They both had some shit to go through and I was happy to see them both go through it together.
The bit at the end though was 100% manufactured tension though. I get the whole thing about how he can't really live on his own and all that, but saying what he said about youkai and humans having to live different lives was utter bullshit. We were given so much proof regarding the opposite, about how much he didn't believe that that putting it right at the end felt incredibly forced. Also it's a bit weird that the brother didn't like to show that he was a youkai, despite the fact that he lived on the other side of the bridge, which inherently meant that he was a youkai more than his neck stretching the way that it did. Or is it youkai and lower class people that lived on the other side of the bridge? Not a great job of establishing that.
All in all though, very solid. The chemistry between the two protags was great, the side characters were all good, and the art was very good as well.