So, no Yosuga no sora thread? BAM!
Tragically orphaned by an automobile accident, the Kasugano twins travel to their grandparents' countryside residence via railcar, hoping to reconstruct the shards of a shattered life. Two lonely souls so physically alike, yet spiritually divergent, they are unaware of the challenges these conflicting expectations will unveil in the days to come. Uncertain of the future, Haruka Kasugano clings to memories of the past, hoping to find the strength he needs to protect his ailing sister. Believing her destiny is irrevocably tied to that of another, Sora Kasugano clings to moments of the present, drawing comfort and security from the company of her brother, who at first does not comprehend how desperately she has fallen for him. Haru, in the later part, learns to accept to her feelings for him and decides that they want to be together, forever. But what if they have to keep their relationship from the whole world, which is against them?

Pretty good anime for me, 12 chapter, 4 or 3 chapters for every girl, happy endings with very cool stories.
Many people get confused watching this anime because every 4 chapters it looks like history is repeating itself and the protagonist chooses another girl from nowhere, that is because it is based on the visual novel and when it ends the story of a girl but the other begins alternatively.

Anyways, if you like romance and incest, i highly recommend you to see it.