the guy is older than her. like, in college while she's in highschool.
at some point it's revealed that he had a crush on her from when he was tutoring her at home?
i think also at some point he introduces her to his family, but i'm not sure if i'm remembering it correctly or getting it confused with something else.

i'm quite sure that's Ashita mo Kitto Koishiteru.

yeup! thanks =)