Ore no Imouto ga Konnani Kawaii Wake ga Nai, Saikin, Imouto no Yousu ga Chotto Okashiinda ga. Recommendations
Both are about a relationship between an older brother and a little sister. At first, in both, the sisters hate their brothers but after some (or maybe a lot) situations, they end up loving them.
This doesn't have that step sister and brother relationship plot but in return a full-blood sibling incest love between brother and sister, which of course the sister is a complete tsundere.
Note: I'm talking about Ore no Imouto here where it's the incest.
Both are about a relationship between an older brother and a little sister. That's another ero anime where the imouto hates the brother at first, but at the end she finally kind of likes him