Sisters' School / Gakuen Shimai

Hentai is based on the relationship between the Nanase sisters - Miku and Arisa. They are beautiful, smart, and also school idols. Therefore, most guys became jealous of the main character, Sosuke-kun, because the sisters started living in the same house with him. It's simple - their parents got married and went on an expedition, leaving the newly-made relatives alone at home...