Alt Title: Oreimo
Kousaka Kyousuke is an average high school student who doesn't get along well with his younger sister, the cute and popular Kirino. Then one day he makes a startling discovery: Kirino's secretly a hardcore Otaku.
Anime [12 Episodes] | OVA [4 Episodes]
This is another one of those anime shows, where all the females have a constant blush. The constant blush makes the show more cute and probably is nothing more than a marketing scheme to attract females to a show that's targeting males.
The basic overall plot to the anime is that Kirino is secretly a hardcore Otaku. She no longer wants it to be a secret, but she doesn't want to loose any friends over the strange fetish she has of little sisters. It's up to Kousaka Kyousuke to do various things throughout the season to make Kirino happy, while keeping both her friends and hobbies.
The show itself makes good use of the visual novel format and allowing the series to end with two different endings. Both endings start off the same, but change dramatically when Kousaka Kyousuke is forced to choose a path. It also does a great job showing the Otaku life and how not all Otakus are socially awkward.
Kousaka is the man. He does so much for Kirino, but still gets treated like a worthless brother. You really start feeling for him after a few episodes and the endings just make you wanna cheer him on. I'm glad they came out with an OVA, but I personally would have liked to see another half season.