http://www.mangago.me/read-manga/suki_ni_nattara_dame_desu_ka/
This one's cute!
Suki Ni Nattara Dame Desu Ka, mentioned above already, is my favourite teacher/student manga, but here are some others I think are good!
http://www.mangago.me/read-manga/koi_ni_nare/ (also has a spin-off about the roommate which is worth reading, http://www.mangago.me/read-manga/koi_nanka_shitakunai/ )
http://www.mangago.me/read-manga/yukidoke_no_koi/
http://www.mangago.me/read-manga/ano_kado_wo_magatta_tokoro/
http://www.mangago.me/read-manga/kitsu_ka_nu_shisen/ (one shot)
ive been looking/interested in reading a teacher x student, no specifics for what role they play. :) any good ones out there.
(=・ω・=)