ジャガーン

Shintaro Jagasaki is a beat cop trudging toward a dull, settled life with his girlfriend when a passenger on his commuter train mutates into a monster. Frogs have been raining over the city, and the ones that latch onto people turn them into "Fractured Humans". In the chaos Jagasaki's own right arm sheathes itself in dark plumage and fires a solid round from his fingers, killing the creature on instinct. Half-changed himself, he is drawn into hunting the monsters across the city, even as the transformation begins reaching people he knows.