Shoujo:
Mayonaka wa Dame yo - A boy who can attain a grown-up body at night by pills
Sensei wa Ore no Mono - As you might guess teacher x student
Shounen:
Anedoki - Middle schooler and high school girl
And two words from me concerning shoujo mangas including older-female-relationships: It's really annoying those damn shoujo authors do not get the decisive point of the female being older. Shoujo heroines 19 out of 20 cases being insecure and weak-willed honestly ist bad enough, but if they choose to portray somewhat older heroines, shouldn't they be, like, mature, confident, self-assured, strong-willed, sort of elevated, dominant to a certain degree or at least a perfect equal to the male partners. I guess you get what I mean...
Why do those shoujo teachers or seniors always make the impression of having escaped preschool - with that kind of bad conscience non the less!
Why, just wanted to get that of my mind...