Three classmates who make their living (literally!) by acting as agents
of the Z-Loan office and dispatching zombies - Chika Akatsuki, Shito
Tachibana, and Michiru Kita - are hot on the trail of an elusive
psychopath known as "The Butterfly." But as if serial killers and
zombies weren't enough to worry about, poor Michiru's barely had a
chace to get used to her new digs, her new life, and...What's this? A new
member!? Chika's friend Shiba joins the teen trio as they solve riddle
after riddle and get ever closer to the madman's lair.