@Kisato I'm reading all of those. I'm just saying that there's a lot more series with M Teacher x F Student than the contrary and wish there were more of later. Thanks for the recommendations though.
@jokerxhisoka I've seen plenty of those but for some reason most of them turn out to be either ecchi or light-hearted comedy, while the opposite mostly ends up most serious and in tragedy. My favourite would probably be that time-leaping highschool boy dating his homeroom teacher.