Sex and the Amars - セックス・アンド・ザ・アマーズ (sekkusu ・ ando ・ za ・ amāzu)
A group of female otaku-- NEETs, hikikomori, fujoshi, etc --all live together in an apartment building. One is obsessed with jellyfish, another likes making dolls, a third prefers buying and playing with model trains and another is obsessed with the Romance of the Three Kingdoms stories. On top of that, there is a popular BL manga artist who is considered the elder of their group despite being rarely seen, even in the house. Collectively, this group refers to themselves as "The Amars." Just like nuns, they shun all boys and only rarely venture into the outside world.
One night, as Tsukimi visits the tank containing her favorite jellyfish, she discovers that the shopkeeper inside has made a mistake and paired it with another jellyfish that could kill the first one. Tsukimi tries to beg the guy to take out the jellyfish, but he isn't interested until a "Stylish" girl appears and offers to buy it for her.
The girl follows Tsukimi back home and crashes in her bed. The next morning, Tsukimi wakes up to find the pretty girl is actually a cross-dressing guy.
Summary
Opening Theme- "Koko Dake no Hanashi (ここだけの話)" by Chatmonchy
Ending Theme- "Kimi ni Kirei no Kizuite Okure (きみのきれいに気づいておくれ)" by Sambomaster