Volumes 1-4 is obviously manga, not anime. There are only one OVA and second one promised 23 Jun. Initially plan was to create 4 OVA, but looks like two - is the most we can hope to.
Manga, on the other hand, is quite active (14 Volumes is out, 15 is expected in April), but it's not scanned (I've sseen only 4 first volumes) and not translated yet...