Finally, the wait for Haiyore fans is over. According to the official website, a prequel to Haiyore! Nyaruko-san (這いよれ！ニャル子さん) will be airing this April and will be titled Haiyore! Nyaruko-san W (這いよれ！ニャル子さん W). This sequel will air in the same season as the prequel. The first season was about deities of the Cthulhu Mythos that are secretly causing chaos in the planet. When the main character gets attacked by an alien, he is saved by a Nyarlathotep. She then decides to stay at his house because she loves him.
Haiyore! Nyaruko-san (這いよれ！ニャル子さん) aired from April 10, 2012 to June 26, 2012. I am not really surprised at the announcement since the sales for the show were pretty good. I have not given this a chance last year and I am not sure I will due to the large amount of shows on my to-watch list. Congrats to everyone who was waiting for this though!
Source: Official Website