Parasyte: Part 1 (2014)

"On a mysterious night, terrible spores suddenly descended on the earth. They penetrated into the human body, taking it as their own, and targeting humans for hunting and devouring. High school student Izumi Shinichi (played by Shota Sometani) also almost had his brain controlled by spores. As a result, the parasitic beast "Xiaoyou" (played by Abe Takashi) living in his right hand..."