First thing I thought when I saw this was "Karin," but the eyes aren't right.

Looks kinda like Konomi from To Heart 2, but she's wayyy over-developed to be her.

Heh, don't blame Leaf for making her (and lots of the other TH2 girls) flat. There's plenty of other dating sims with overly-endowed heroines (or masturbation fodder, as you prefer).