How many times do I still have to tell about the difference between a publisher, a label and a studio?
ZIZ Entertainment is nothing but a label, it never has been a studio (producing animations), because it never has produced a single animation, the only videos they produced have been real life adult video adaptions of Lilith games (JAV).
The publisher behind the labels Lilith, Pixy, Ordin Soft, Valkyria++ and ZIZ Entertainment and all their sublabels is
Infini-brain Inc. ->
http://www.infini-brain.co.jp/
The studios producing the last releases of the ZIZ Entertainment animation label were:
Makai Kishi Ingrid: Re - Mesu Buta Dorei ni Ochita Makai Kishi / 魔界騎士イングリッド: Re~メス豚奴隷に堕ちた魔界騎士~ = studio:
TEATRO西東京スタジオ (TEATRO Nishi Toukyou Studio)
Zoku Tsuma Netori: Ikumi to Shizuka / 続・妻ネトリ 郁美と静香 = studio:
TEATRO西東京スタジオ
Ryoujoku Rinne / 凌辱輪廻 = studio:
TEATRO西東京スタジオ
Jukujo Shigan / 熟女志願 = studio:
MB企画 (MB planning)
Taimanin Asagi 3 / 対魔忍アサギ3 = studio:
Studio Eromatick
The ZIZ Entertainment (Animation) label [established 2012] just is the successor label of Pixy.
Animation labels come and go, they are changed just like your pants, I have seen many many coming and vanishing over all these years since the first hentai animation in February 1984 (Lolita Anime Wonderkids part 1), and I have seen many publishers and studios come and go. It is just something like a natural process...
If there isn´t enough profit to be made with hentai animations the publishers just let this part of the business die, examples are the AnimeOnDemand / Binetsu 37°C labels of publisher SoftOnDemand or the *EDGE label of publisher K.M.P (K.M.Produce). Most of the animation publishers / labels are / were owned by the japanese porn industry where animation just were the smallest part of their business, and it is cheaper to produce a porn video than an animation.