Nisemonogatari, Oniichan dakedo Ai sae Areba Kankeinai yo ne! Recommendations
Both are heavy on the ecchi specifically with sexual situations.
Both have mostly female driven ecchi scenes
Both have a large focus of the content on an incestuous relationship between bro x sis
-Nise's Art is better.
-Nise has a better plot.
-No monsters/demons/vamps ect are in Onii-Chan.
-Onii-Chan is more focused on comedy than drama.