Alternate Titles: Kiseiju
Shota Sometani, Eri Fukatsu, Ai Hashimoto
One night by the seaside, tiny creatures or "Parasytes" arrive on Earth to take over human bodies and prey on human kind. One Parasyte latches on to a regular high schooler, Shinichi but he prevents it from completely taking over his mind and body and instead it has to start a reluctant existence in his right arm. Shinichi cannot reveal his terrible secret to those around him, and during this time of stalemate, a feeling almost of friendship develops between him and the creature he calls "Migi" ("Righty"). Before long, they begin to encounter other Parasytes which launch savage attacks against them and put the life of his childhood friend, Satomi in danger…
Then things take a sudden turn for the worse. Shinichi's beloved mother is killed and taken over by a Parasyte. When the creature launches an attack on him, he has no choice but to kill her. It becomes all-out war. Parasytes kill humans and humans kill Parasytes in return. But nothing is black and white in this struggle. Among the Parasytes themselves, various factions and different points of view, develop. Shinichi's new teacher, Ryoko Tamiya, although infected with a Parasyte, tolerates Shinichi. On the other hand, the character Goto, a composite "person" made up of a number of cooperating Parasytes is bent on human destruction. Collectively the Parasytes begin to ask themselves the question, "Why were we created?"
In a world that humanity has continued to despoil and destroy, is it that the Parasytes are here to cull our numbers? Of course the humans continue to kill Parasytes in order to survive.
Which is it that ought to win? The planet needs to be preserved yet it is in our nature to protect our loved ones. Amidst this conflict of values, Shinichi and Migi have no choice but to hurl themselves into the fight against the ever more complex attack of the Parasytes.