Kare First Love

Karin Karino is a 16-year-old girl who wears glasses and suffers the taunts of her fellow students. Since she's not one of the ultra-popular beauties at school, she considers herself unattractive.

Kiriya is a boy at the same school and he ends up falling for her and giving her her first kiss. Although she tries to reject his advances at first (what is termed "self-defense mechanisms") she ends up slowly coming to really like him.

That would not be too bad except another girl wants him. She pretends to be Karin's friend, but ends up competing with him for Kiriya's affections.

It's a somewhat unusual approach to romantic problems in high school and is quite good.