Swing Out Sisters

A high school guy with a siscon and his tow sisters, one that's busty and one that's much less. The guy has more feelings for the busty sister. Both have similar art styles, but Swing Out Sisters is a hentai and Aki Sora just extremely ecchi. They both have similar feelings with a little comedy and drama mixed in with the incestual sex. 

Both well animated hentai titles featuring a brother engaging in sexual intercourse with two sisters, whom compete for his love. Both titles include a sister with larger breasts as well as a more petite sister with smaller breasts.