Based on the doujin fighting game Melty Blood, created by the doujin group Watanabe Seisakujou, now known as French Bread. The story is one of two side-story sequels that take place approximately a year after the good ending of Arcueid's route in the original Type-Moon game, Tsukihime. One year has passed since the "Serial Vampire Homicide case" from Tsukihime was solved. However, rumors of serial murder are circulating again, so Shiki Toono once more patrols the city to find this phantom killer. While patrolling, he meets and fights a mysterious woman named Sion Eltnam Atlasia, a member of the church group 'Alchemist of Atlas,' who is searching for a cure for vampirism. To achieve this, she needs data from Arcueid, the last True Ancestor, to aid her research. This will not be easy, as Ciel is also patrolling the city looking for the rumored killer, while Akiha has been acting strangely over the past few days. Furthermore, Arcueid has not been seen for a while; could she be the killer...?