Based on Iwaaki Hitoshi's science-fiction horror manga by the same name.
The 17-year-old Izumi Shinichi lives with his mother and father in a quiet neighborhood in Tokyo. One night, worm-like aliens called Parasytes invade Earth, taking over the brains of human hosts by entering through their ears or noses. One Parasyte attempts to crawl into Shinichi's ear while he sleeps, but fails since he is wearing headphones, and enters his body by burrowing into his arm instead, taking over his right hand and is named Migi.
Because Shinichi was able to prevent Migi from traveling further up into his brain, both beings retain their separate intellect and personality. As the duo encounter other Parasytes, they capitalize on their strange situation and gradually form a strong bond, working together to survive. This gives them an edge in battling other Parasytes, who frequently attack the pair upon realization that Shinichi's human brain is still intact. Shinichi feels compelled to fight other Parasytes, who devour humans as food, while enlisting Migi's help.
|Migi main||Aya Hirano Japanese|
|Shinichi Izumi main||Nobunaga Shimazaki Japanese|
|Satomi Murano main||Kana Hanazawa Japanese|
|A supporting||Makoto Yasumura Japanese|
|Mitsuo supporting||KENN Japanese|
|Taku Furudani supporting||Junya Enoki Japanese|
|Makiko Hayase supporting||Yuu Serizawa Japanese|
|Takeshi Hirokawa supporting||Yuu Mizushima Japanese|
|Kazuyuki Izumi supporting||Masaki Aizawa Japanese|
|Nobuko Izumi supporting||Chieko Sasai Japanese|
|Kamijou supporting||Yuya Murakami Japanese|
|Kana Kimishima supporting||Miyuki Sawashiro Japanese|
|Kazuki Nagai supporting||Shinya Hamazoe Japanese|
|Sasaki supporting||Tooru Nara Japanese|
|Hideo Shimada supporting||Akira Ishida Japanese|
|Akiho Suzuki supporting||Rena Maeda Japanese|
|Yuuko Tachikawa supporting||Kiyono Yasuno Japanese|
|Ryouko Tamiya supporting||Atsuko Tanaka Japanese|
|Mother Tamiya supporting||Seiko Fujiki Japanese|
|Mamoru Uda supporting||Takuma Suzuki Japanese|
|Uragami supporting||Hiroyuki Yoshino Japanese|