Kiss x Sis (TV), Yosuga no Sora: In Solitude, Where We Are Least Alone. Recommendations
Both are ecchi to high levels and handle the idea of an incestious relationship between siblings.
Both are on the borderline of being a hentai. You do not see anything but you know what is going on.
Brother-Sister incest. Ecchi. Though it seems that Yosuga no Sora will have a more intriguing storyline
incest relationship, and a harem in both. Yosuga no Sora has a much better story line than Kiss x Sis and also is rated R+ because there is nudity in majority of the episodes. If Kiss x Sis was good for you then Yosuga no Sora is even better.
Good anime for masterpiece fap
Same aspect here, a sister liking her brother, IMO yosuga no sora had a better story and just wasn't also ecchi every time, this anime is very similar.
Both are borderline hentai anime focusing on raunchy incest scenes and ecchi through the eyes of a boy and his harem.
Both are ecchi and in both anime is about love between brother and sister/s (siblings)
Genre for both anime: Ecchi, Romance, Harem... :D