Grimoire is a shop in Shibuya, Tokyo selling antique/vintage clothing, accessories, etc. associated with Dolly Kei. There is also a "sister store" named Grimoire Almadel. The name "grimoire" means: "a textbook of magic".
Grimoire is not a Lolita brand by any means.
Grimoire's original tights and socks are popular among lolitas because of their loliable aesthetic.