The story is one of two side-story sequels that occurs approximately a year after the good ending story of Arcueids from the original Type-Moon game, Tsukihime. One year has pass since the -Serial Vampire Homicide case- was solved with both the deaths of Nero (Nrvnqsr) Chaos and Roa/Shiki Tohno. But now the rumors of the serial murder are happening again and so once again Shiki Tohno patrols the city to find this phantom killer. While patrolling he meets and fights a mysterious woman by the name of Sion Eltnam Atlasia, member of the church group -Alchemist of Atlas-, whom is in search of curing vampirism. But to do so she needs data from Arcueid, the last True Ancestor, to help her in her research. But this wont be easy as Ciel is also patrolling the city looking for the rumor killer, while Akiha has been acting strangely the past few days and also Arcueid has not been seen for awhile, could she be the killer...?