This game has been released recently and I must say it's better than I thought it would be =D
The premise is having a love affair with your own brother, however, the protagonist and her brother are not blood-related so it's a "safe" enough game ^^;
Also, although I do not have some sort of brother-complex, I've been enjoying the story a lot because the game seems to take itself very seriously... once outside of the tutorial course XD