Ren is an ordinary student walking home through a dark, rainy alley when he hears a mysterious voice calling from the shadows. Suddenly, an ancient dragon mark awakens on his chest. Purple-black flames surround him, and his eyes begin glowing with supernatural power. A mysterious entity named Kurojin reveals itself—a powerful shadow dragon that has been waiting for centuries. It tells Ren that they are now connected as one. As Ren struggles to understand what is happening, his new powers begi
