The manga adaptation of the successful light novel series Ore mo imoto ga konna ni kawaii wake ga nai (known by fans as Oreimo for short). The Oreimo manga is a collaborative adaptation by artist Sakura Ikeda and Oreimo creator Tsukasa Fushimi. Ikeda's manga version has made the top-10 bestseller list in Japan, and, as Fushimi discusses in the afterword to Oreimo vol. 1, Ikeda's manga has actually influenced the way the Oreimo novels have developed, as well.
Oreimo (also known through the anime series released in North America by Aniplex) is the story of high school student Kyosuke Kosaka, who one day discovers his sister Kirino, whom he barely ever speaks with, has been leading a secret life as a fan of dubious anime and PC games. At first he tries to cover up her hobbies because he knows their parents will disapprove of her being an otaku, but soon Kyosuke finds himself drawn into Kirino's world and her circle of friends, as well as the state of being a modern "professional fan" in Japan's otaku scene, events, and neighborhoods.
Oreimo Vol. 1 will be released by Dark Horse in September 2012.