Parasyte: Part 1

Tiny creatures called "Parasites" have arrived on Earth with the sole purpose of taking over human bodies and preying on mankind. One such Parasite latches on to ordinary high school student, Shinichi Izumi. Fortunately, he is able to fight it off before it reaches his brain. But unfortunately, it is now stuck within his right hand. Shinichi cannot reveal his terrible secret to those around him, but a strange relationship develops between himself and the creature he calls "Migi" (Righty). Before long, they begin to encounter other Parasites which launch savage attacks against them and endanger the life of his childhood friend, Satomi.