The younger of the two twin maids in the Tohno mansion. She wears a western maid uniform and attends to Shiki when he comes back to the Tohno mansion. Her name, Hisui, is the Japanese word for jade, referring to her eye color.
She acts cold and unfeeling, but it is only an act to hide her kinder nature for the sake of her sister. She is a Synchronizer, a person that can give someone life energy through the exchange of body fluids.
from Wikipedia entry
Related anime:Lunar Legend Tsukihime TV, 2003
Carnival Phantasm OVA, 2011
Carnival Phantasm: EX Season OVA, 2011
Carnival Phantasm: HibiChika Special OVA, 2013
Related manga:Lunar Legend Tsukihime Manga, 2003
Take Moon Manga, 2004
Melty Blood Manga, 2006
All Around Type-Moon Manga, 2008
Related games:Lunar Princess H-Game, 2000
Ten Nights of the Singing Moon H-Game, 2001
Melty Blood Act Cadenza Ver. B Video Game, 2007