Oreimo: My Little Sister Can't Be This Cute

Ore no Imouto ga Konnani Kawaii Wake ga Nai (俺の妹がこんなに可愛いわけがない, Ore no Imouto ga Konnani Kawaii Wake ga Nai, lit., My Little Sister Can't Be This Cute), also known as Ore no Imouto or Oreimo, is a light novel series published by ASCII Media Works under the Dengeki Bunko imprint. It tells of the story of a normal high-school student who stumbles upon the unusual hobby of his younger sister, who turns out to be an otaku. The light novels were adapted into a manga series with illustrations by Sakura Ikeda which is published on ASCII Media Works' Dengeki G's Magazine. An anime series adopting the events from the light novels aired between October and December 2010, with additional episodes airing between February and May 2011. The anime series was produced by AIC and consists of 12 episodes.

Plot
Kyosuke Kosaka, a normal 17-year-old high school student living in Chiba, has not gotten along with his younger sister Kirino in years. For longer than he can remember, Kirino has ignored his comings and goings and looked at him with spurning eyes. It seemed as if the relationship between Kyōsuke and his sister, now fourteen, would continue this way forever. One day however, Kyosuke finds a DVD case of a magical girl anime which had fallen in his house's entrance way. To Kyosuke's surprise, he finds a hidden eroge (an adult game) inside the case and he soon learns that both the DVD and the game belong to Kirino. That night, Kirino brings Kyosuke to her room and reveals herself to be an otaku with an extensive collection of moe anime and younger sister-themed eroge she has been collecting in secret. Kyosuke quickly becomes Kirino's confidant for her secret hobby.