Ore no Imouto is about a normal high school student who has a little sister that is secretly an otaku.
The main character (Kyousuke) is a pretty chill guy while his sister (Kirino) is essentially a tsundere. I thought this series would end up being ecchi-oriented or something, but it has actually turned out quite nicely. The comedy stems from the character interactions, such as Kirino forcing her brother to play through an eroge so she can discuss it with him.
Aside from the comedy, the story gives a serious look into the acceptance of the “otaku” culture. Kirino is afraid of the negative consequences of revealing her hidden hobby, so she goes to great lengths to hide it. Her father makes it abundantly clear during family dinners that he disapproves of anime. Sooner or later, Kirino’s parents and school friends will probably find out about her hobbies. I’m curious to see how she (and her brother) will handle the resulting situation.
With Ore no Imouto thrown into the mix, this Fall 2010 anime season is shaping up to be the best we’ve had for a while.