mishe's Things

I cant remember the title of a shoujo manga and probably josei. It was about a guy who only gets hard with his ex. They broke up a long time ago in high school i think. Then they meet again and they lived in the same house and the ex gf helped him to fix his problem with getting hard. I hope you can help me whats the title of this haha

Any historical recommendations where there is no isekai but as good as the one with isekai.....