Sirius the Jaeger unfolds in 1930, when vampires have infiltrated Tokyo and begun feeding on unsuspecting citizens. As the death toll rises, the city's authorities hire the Jaegers, a strange and diverse team assigned by the V Shipping Company to hunt vampires around the world. They travel with musical instrument cases to conceal their weapons and identities, and when the fighting begins, they answer their enemies with the same mercilessness the vampires show their victims.
At the center of the story is Yuliy, the Jaegers' most skilled warrior and the sole survivor of a vampire raid on his home village. Empowered by his werewolf blood, he works alongside the rest of the team in their apparent effort to assist Tokyo's police, though their real mission is far more dangerous. The Jaegers are chasing the mystical Ark of Sirius, an artifact said to hold the power to change the fate of the world. With the vampires pursuing the same prize for destructive ends, Yuliy and his allies must find the Ark before their enemies can claim it.
