Your description was indeed alluring, but I can read "Keep in mind the story is really not sexual" about that title... Muh. I saw at most a few kisses, nothing more. Sorry, useless, and infinitely boring.
Huge gap AND realistic sex-related issues = Koi Kaze, you won't beat that.
I hate purely romantic stuff because it's so unrealistic.
Keep in mind this story is about a mother and her child who have always lived together knowing they were family... it would be unrealistic for a mother to just glomp her child and be all sexual within a few chapters.
Koi Kaze involved a brother and sister who were separated when she was very young... and when they first met after becoming adults, they did not recognize each other. They fell in love thinking they were complete strangers. They didn’t find out they were siblings till the pops showed up. In the end they were ok with their sexual relationship because they pretty much lived apart for most of their lives unlike bro and sis anyway.
BIG difference.
Also, I happen to know couples who share a sweet, pure relationship outside of their bedroom...They still have sex... pure relationships are definitely real. And the girl and guy did start out sweet in Koi Kaze lol...