Ore no Imouto ga Konna ni Kawaii Wake ga Nai Portable is a PlayStation Portable visual novel developed by Bandai Namco Games and released on January 27, 2011. The limited edition bundle will include an OAD, a sister-talk bonus CD, and an additional game for the PSP.
Unlike the original story of the light novels, Oreimo Portable expands on the story, with complete story routes for Kyousuke and each of the main female cast written by the original creator of the light novels, Tsukasa Fushimi.
The plot in Oreimo Portable acts as a spin-off to the light novels, which explores on the relationship between between Kousaka siblings Kirino and Kyousuke. The story begins the year after Kirino's infamous "life consultation" with her older brother, who accidentally discovers her darkest secret: that she is an avid fan and collector of anime and eroge involving older brother-little sister dynamics.
After Kirino returns from her trip to the United States, she and Kyousuke continue on the usual antics, with their friends Saori Bajeena and Kuroneko tagging along. At this time, Kuroneko is starting to become close to Kyousuke during Kirino's absence, and their relationship is used by Kuroneko to tease Kirino, who is her rival to Kyousuke, and — surprisingly — her best friend.
The player assumes the role of Kyousuke Kousaka, whose life as a mediocre person is changed by his 'life consultation" session with the little sister whom he has learned to ignore. The story later develops into Kyousuke's experiences with the different girls who have interacted with him, including Kirino, her best friend Ayase Aragaki and her classmate Kanako Kurusu.