Archimedes

Archimedes is a stuffed cat-like doll that Ojou carries around in her arms all the time. One of its strange abilities is that it is able to talk just like a normal human being albeit without opening its mouth. To a stranger, it appears like Ojou is using ventriloquism but that is not the case. It's not known why or how Archimedes is able to communicate with humans and its origin is certainly one big mystery. His main purpose appears to be that of Oujo's protector and a reliable traveling companion.