MISC. MANGA, *Gou-Dere Sora Nagihara

This manga is by Suu Minazuki, the creator of Heaven's Lost Property, and it carries a very similar theme of a random horny teenage boy getting an otherworldly love interest seemingly out of nowhere, although this one currently doesn't have an anime based on it. This has been one of Minazuki's on-and-off projects as he's been doing it since 2008, but only about 4-5 collected volumes have been printed so far.

Shouta is an otaku who has a serious fix on 2-D girls, and not real life flesh 'n blood girls. He's totally hung up with a cat-eared schoolgirl named Sora, and somehow she comes out of Shouta's graphic novel and into the real world, even though her personality in this reality is much more rough and aggressive than her fictional background. Sora declares that Shouta is officially her master, and is for some reason destined to take over the world. From this point on, Sora keeps bringing over girls to Shouta's dorm room for him to impregnate to help expand his "dynasty". This ends up getting Sora arrested several times, and eventually kicked out of the dorms. However, his childhood friend Ryoko(who got him kicked out in the first place)offers to take him in, and Shouta is shocked to discover that her father is actually the creator of the manga Sora came from. Later on, another version of Sora arrives claiming to be the "real" one, leaving the first Sora's origin to be much more questionable.

This story is pretty decent so far, although its kinda clear that Minazuki works on this title sparingly from time-to-time. It's very much not for younger readers, but its not a full-on hentai title either. Give it a look as its just now finally coming out in America through Yen Press.