oppao-san

An original character by chiwino. Has long black hair, purple eyes and large breasts. Her full name (and the name chiwino uses) is black-haired oppao-san (黒髪のおっぱおさん).

Her name is most likely taken from the word おっぱお (oppao). The word made its first known use on Hikaru Ijuin's radio show Shinya no Barajikara (深夜の馬鹿力) on 11/1/2004 as part of his joke material.

子供A「「いっぱい」の「い」を「お」に置き換えて言って見ろ」
子供B「お・・・おっぱい？」
子供A「バーカ、おっぱおだよ。おっぱいだって、おまえスケベだな」

スケベで何が悪い！男は皆、おっぱいが好きなんだ！！（多分）

Translated:

Child A: "Tell me what you get when you replace the 'i' in 'ippai' (a lot) with 'o'."
Child B: "O… 'oppai'?"
Child A: "Duuuumy, you get 'oppao'. Thinking about boobs, you're such a pervert."

What's so bad about being a pervert! All men like boobs! (probably)