Black Bloods and Red Bloods, vampires and humans. Despite their differences, these two races once fought together in a crusade against a formidable foe. A decade later, the vampire war hero Jirou Mochizuki, known as the "Silver Blade," travels with his younger brother Kotarou to the Special Zone—a safe haven where vampires and humans live in harmony. However, their journey is suddenly faced with danger when a conflict erupts between vampire migrants and human forces from the Special Zone. With the rise of a developing conspiracy from an old enemy, Jirou will need the help of his new ally, Mimiko "Compromiser" Katsuragi, as well as the power of his ancient bloodline to protect what he treasures the most.