Yoko Ueda

Touch not the Outsiders, lest ye become an Outsider. But when two creatures belonging to opposite kinds - a lost little girl from the Inside and a demonic beast-looking Outsider - initiate an impossible coexistence on the same side of the forest, their bond seems to transcend their incompatible natures and the unnamed curse that has divided the world.

The three brothers discover that the human experiment banned after destroying the "Orochi", is still going on to secretly revive the evil snake. They also find out that some ex-members of the Yamainu (the Japanese military unit formed to kill the snake) are behind this conspiracy. The brothers fight together again in a battle against the military.