Okozukai Kasegi no Amai Koe

An original work about compensated dating.

Miyuki is a big-breasted, prim-and-proper looking school girl with a short haircut. Her body is that of an early bloomer that's still not finished growing and she lets it be dirtied with some well-lit sex in exchange for money.

(Source: Melonbooks)

Note: Originally 2 doujin books, later published as 2 heavily censored chapters by Night Comic.