Shiki's classmate, who has had a crush on him since middle school. She takes a slightly larger role in Tsukihime the game and Melty Blood.
SpoilerAfter she became a dead apostle she could use a Reality Marble called "Depletion Garden", which rapidly decreases the mana of the area where the Reality Marble is expanded. It is extremely effective against Magi who need mana to attack or Elementals that require it in order to exist, but it has no actual effect on creatures that are cut off from the world.In TsukihimeSpoilerWhen she goes to investigate rumors about Shiki wandering around town late at night, SHIKI appears and bites her, turning her into a vampire. Most people simply die or possibly turn into a weak zombie when bitten, but Satsuki was an extremely rare exception who not only became a vampire, but quickly gained control over her powers as well.In Melty BloodSpoilerShe seems to have become good friends with fellow tragic vampire Sion, and together forms the "Back Alley Alliance". Riesbyfe later joins the Back Alley Alliance too.