Sometimes I feel not enough thought is given to Haru and Ren's sexuality, especially when they are so fascinating and complex representations.
One could argue Haru was perhaps demisexual in the sense he had never actually fallen in love until he met Ren and shared a deep emotional connection with him. The manga itself certainly alludes to him falling in love with Ren when they first met. After they bonded and he realised Ren could see past his "mask". He's certainly never been in love prior to Ren, at one point even admitting to himself that he only went out with girls because he did not care what they thought of him and they were expendable. There was no emotional connection there. Not even with the woman he slept with when he was in care - it was out of loneliness and he admitted that as well. He never tried to contact her after he was thrown out of the home and he never went looking for her either. Obviously there was that one moment when he was about to call her after being given her number, but that was because he was conflicted with his feelings towards Ren and was trying to force himself to be "normal", thinking Ren might not fully feel the same way. It's only after Ren tells him he should do what he really wants that he decides to pursue Ren. Of course, a misunderstanding takes place just as he does so, but it's all sorted out soon after.
Overall, I'm pretty sure Haru is demisexual. And before anyone points out he had sex with others so he can't be - that's not true. Some demisexuals can and do have casual sex for whatever reason (loneliness seems to be a factor in Haru's case), but there is just no real attraction there.
As for Ren? I'd say he is also demisexual. Some might perhaps claim he's asexual, but I would have to disagree. Ren has shown sexual attraction towards Haru on numerous occasions, too many to list! He does not show any attraction to anyone other than Haru, who he has a deep connection with. So I think it's safe to say he's likely demisexual as well. And personally, I think it's perfect that way.
