When the seal for Nora's form is released he becomes Cerberus, the vicious dog of disaster. But Nora can only use magic when Kazuma grants him permission...and Kazuma doesn't grant permission easily. The Dark Liege wants the two to team up and crack down on renegade demon factions in the human world, but how can they do that if they can't even get along?
Nora's presence on Earth has made him a target for renegade demons. But when he uses magic to fight them, it takes a toll on Kazuma's body! The Dark Liege sends Kazuma a ring to counteract this effect, but what Kazuma really needs is information on the legend of Cerberus, Nora's true form. Too bad the one with the info is one of the demons he's fighting!
Nora and Kazuma learn that the Resistance is out to defeat Dark Liege by destroying her five Soul Stones: jewels from the Demon World that have made their way to the Human World. Nora soon discovers he has a special ability to detect these gems...but he's not the only one!
Nora and Kazuma head to a location where the Resistance is collecting Soul Stones...but then the seal spell on Nora is broken! With Kazuma's commands no longer having any effect, will Nora go on a mad rampage as Cerberus? Or can Kazuma find another power source before it's too late?
After two long months apart, Nora and Kazuma meet again...and Kazuma's ready to teach his stray dog some new tricks! Is he older and wiser, or just more of a pain in Nora's backside? Either way, the guys don't have time for an emotional renuion. They're finally about to face the elusive leader of the Resistance!
Having survived their battle with the Resistance leader, Nora and Kazuma learn about the history of Cerberus and the Dark Liege's previous incarnations. In doing so, they discover the pivotal role Nora must play in the balance of the Human and Demon Worlds...and the reason Kazuma was chosen to work with Nora.
The Resistance, led by Fall, begins its siege on the Dark Liege's headquarters. Due to the immense power Fall gained in his encounter with the previous Cerberus, the Dark Liege faces a tough battle indeed...and as Nora and Kazuma rush to aid her, each must struggle with his own inevitable role in destiny.
At long last, Nora and Kazuma face Fall in a final battle. But not only is Fall overwhelmingly powerful, he surprises our heroes by taking the battle to the Human World! Will changing into Cerberus give Nora the power he needs to face Fall's true form and stop the demonic invasion of Earth, or will Kazuma be forced to make a brutal sacrifice?
Final Volume!Now charged with the powers of the Dark Liege, Nora has the ability to restore the balance between the Human World and the Demon World. But he can't do it without Kazuma, who just wants to go back to being a normal super-cool genius. With the two worlds colliding, it's time for Nora and Kazuma to join forces again…and for Nora's collar to come off!