Vampire Yui: Kanonshou  

Yui Kanonsho: Lost Memories, Vampire Princess Yui: Kanonshou, Kyuuketsuhime Yui: Kanonshou, 吸血姫 夕維―香音抄

The story of Yui and her travels though time with her Guardian Nagi, how they live in death and struggle within their own memories to recall who they once were.

Vampire Yui: Kanonshou was partially published in English as Yui Kanonsho: Lost Memories by Studio Ironcat.