Satsuki Yumizuka, Sion Eltnam Altasia, and Leez are societal outcasts who live in an alley, hidden from the public eye. Both Satsuki and Sion are vampires, and together with Leez, they have been drifting aimlessly since the events of Tatari. Sion decides to use her alchemy powers to build proper living quarters for the group, but something goes horribly wrong, resulting in a 100-meter pyramid appearing in the middle of the city. Suspecting foul play, the trio investigates the pyramid and manages to get things under control. Based on the Tsukihime and Melty Blood games, you will be introduced to other familiar characters like Kohaku and Akiha.