I need help, I'm looking for this manga

I need help, I'm looking for this manga I've read a long time ago. I remember that the plot was that people in this town were different from other people, they needed a partner to help them to breath. Their partner would put their mouth on them like they are kissing, but it helps them to breath and if they don't do that then they would die since they can't breathe like a normal person and need their partner to give them air once in a while. I think it was a Shounen Ai, but I remember it had a straight couple in one of the chapters.