Parasyte centers on a teenage boy named Shinichi Izumi. He lives with his mother and father in a rather quiet neighborhood when, one night, an alien invasion occurs. The aliens are called Parasites. They are worm-like creatures that enter human "hosts" through their ears or noses, and take over their brains. A Parasite attempts to crawl into Shinichi's ear and take over his brain while he sleeps, but is stopped by his headphones and accidentally burrows into one of his hands instead. In the Japanese version, it takes over his right hand and it is named Migi (ミギー ?), after the Japanese word for "right".[3]
Because the Parasite infected his hand instead of his brain, Shinichi and Migi each retain their own, separate intellect. This gives them an edge in battling the other Parasites, who see Shinichi's ability to think independently as a threat. Shinichi also feels compelled to fight other Parasites, who kill and eat humans as a source of food.
