Ore no Imouto ga Konna ni Kawaii Wake ga Nai Portable

俺の妹がこんなに可愛いわけがないポータブル

The first Oreimo visual novel game for the PSP. When released, it featured some storylines that were not yet revealed in the TV series. Has various scenarios including What if... scenarios for stories that go beyond what one would expect out of the characters.