According to the notice from Fantasia Bunko, an OVA of this winer anime Kore wa Zombie Desu ka? will be bundled with the limited edition of the original novel volume 8. It is the series' episode 13, which will not be aired on TV. The release date is June 3rd 2011.

Kore wa Zombie Desuka? official website

Staff of the series
Director: Kanasaki Takaomi
Series Composition: Uezu Makoto
Character Design: Tagashira Shinobu ("Da Capo", "Shounen Onmyouji")
Production Studio: Studio Deen
Theme song: Nomizu Iori

Cast of the series
Haruna: Nomizu Iori
Aikawa Ayumu: Majima Junji
Sera: Hikasa Yoko
Tomonori: Kanemoto Hisako

Source: Scan of the notice

Kore wa Zombie Desu ka? OVA on MAL