Majimoji Rurumo had an 12 episode Anime back in 2014. For those who know just a bit like myself this news may had came out of no where as Majimoji Rurumo source material, a manga by the same name, had ended before the anime in 2010. Little did I know. Majimoji Rurumo: Makai-hen is a contenuation of the orginal manga. Ending in 2013 before Majimoji Rurumo: Houkago no Mahou Chuugakusei manga which runs till today. The OVA is to be bundled with the 9th volume of the current manga. But overall there has been 11 volumes between the first two mangas making the 9th volume the 20th related with Majimoji Rurumo. A longer running manga then I knew about.
the new anime will be based on the Magimoji Rurumo: Makai-hen manga, it will tell an original story. As the manga is simply a continuation of the original Majimoji Rurumo manga, the OVA would likely make a good conentuation for the Anime that came out in 2014.
Shibaki is a high school boy only interested in girls. However, he has been branded as the most perverted boy at school, and the girls go out of their way to avoid him. When he finds a book in the library about how to summon witches, he tries it as a joke; unexpectedly, though, the book works, and a cute witch named Rurumo appears to grant him a wish. Shibaki helps Rurumo and she in return refuses to take his soul.myanimelist.net
After some time, he thinks about his meeting with Rurumo, and wishes he could see her again. His wish is granted immediately, as Rurumo falls from the sky and crash-lands in front of him, tasked with getting him to use up 666 magic tickets that grant wishes before she can become a witch again. However, according to Rurumo’s familiar, what she does not know is that each ticket he uses will shorten his life span, and, when the last ticket is used, he will die.