I've watched Majou no Joken and Biscuit Teacher Star Candy and loved both dramas and their concepts... I was wondering if u guys have some good drama with this theme! It can also be a regular noona romance recommendation if you have a really good one :D
Thanks!
Flower Boy Ramyun Shop
Sapuri - she's his senior at the advertising company and in charge of his training.

I collect Noona Romances on my blog, here's my full list of the shows that I've discovered are all older woman/younger man relationships.
These are noona romance but not teachers
High School King of Savvy
Let's Eat
Me too, Flower

No teacher-student relationship, but still older female/younger male: 
I hear your voice (kdrama) ♥♥
Anego (jdrama) ♥
Kimi wa petto (jdrama) / You're my pet (kmovie) ♥
Last Cinderella (jdrama)
Sore wa, Totsuzen, Arashi no you ni..(jdrama)
Thanks guys <3
I'll check all those recommendations out! ^^