Ore no Imouto ga Konnani Kawaii Wake ga Nai, Yosuga no Sora: In Solitude, Where We Are Least Alone. Recommendations
In Oreimo, we follow our mc Kyouske and his three different girls(I think), with one in each arc. On the other hand, Yosuga no Sora also has different arcs but with more... ecchi *cough* *cough*
- both deal with their little sister
However one deals in a more friendly way (oreimo)
And yosuga no sora deals with more a forbidden relationship
Both titles are about typical high school boy and his harem, including little sister. Every female heroine has its own arc, but the main is incest one. As for Oreimo, it's more a romantic comedy, and Yosuga no Sora is a drama about forbidden love.
Same type of love story, which is incestual relationship between brother and sister. While in Yosuga no Sora it is described in a serious way, in Oreimo, it's more focused on the comedy side.
The unfolding of the two anime is similar: the protagonist is surrounded by several female characters who all serve as love interests. But the main girl remains his sister, who is jealous of her brother's suitors.
Also, each girl has her own arc. However, the final arc is in both shows focused on the little sister.