Zakuro is a stone puppet made by Hakubi with a special stone (garnet) and his own blood. Hakubi considers it his friend, even if it's just a puppet. It was sent by Kinrei, along with his master, to attack Rakan and his comrades but ended up devoured by Kuro.

Later on it's revealed that Zakuro is a little different than the other stone puppets because it was made from a stone that "evolves" and had gained some kind of consciousness.