Koseki Bijou's dark katana, introduced with her third costume. Its blade is made of the same purple gemstone as her chest jewel (and, this costume implies, the rest of her body under her human-appearing skin), and the guard and pommel are crystals of the same gem. Its name is a play on Yamato, Vergil's sword from the Devil May Cry series, and is (usually) pronounced "to-mah-to".
