Anime impressions: Parasyte

Thoughts and analysis on this surprisingly deep anime. Spoilers!

published 2022-Mar-08, updated 2022-Sep-05

Link: https://en.wikipedia.org/wiki/Parasyte.

Very competent writing. The writers did their homework on biology and ethics, and it shows. Very well thought out. Deeply thought-provoking. Carefully averts common anime tropes. Not your typical "shonen" anime.

Parasyte does have a few deus ex machina moments and out-of-character scenes. To me they feel forced, like if a meddling executive wanted to make a certain point and had it shoved in without consulting the original author. Two examples come to mind. One is the final scene in Hikari Park, where I feel like both present females and to a lesser extent Shinichi act horrendously out of character, with nonsensical out-of-context lines. Other is the beginning of the last episode, which, while containing some cool ideas, seems forcibly inserted to create a "happy ending" for the more squeamish viewers who can't fully accept what happened up to that point. Otherwise, most of the writing seems extremely solid and well thought.

The series pays careful attention to biological details. It seems that after coming up with the general concepts, the authors gave a lot of thought to the implications of parasite biology, and made them into plot points.

I initially found it implausible that parasites tend to master language and learn immense amounts about the human society, technology, and customs in just a few hours, often having little to no contact with the stuff. But given the parasites' aptitude for mimicry and being one large "sentient muscle", this isn't that implausible. In order to take over a living body without killing it, then maintain and control it, the parasite assimilating the brain must learn and replicate its structure on the fly. This might give them the human's subconscious skills such as language and social customs. They don't seem to receive higher-level stuff like formal knowledge and memories.

The series explicitly points out that non-head parasites have to learn language from scratch. It slightly stretches belief in the beginning, when Migi utters its first words next morning, having never heard those words before. But for the most part its learning speed is handwaved by reading tons of books and encyclopedia articles really fast. This seems to become a habit: throughout the entire series whenever Shinichi and Migi rest at home, Migi is shown reading. This explains many of the differences between Migi and other parasites, and shows how much attention to subtle details went into the writing.

Non-head parasites perform the same on-the-fly mimicry while assimilating non-brain structures such as an arm or jaw/neck/chest. They can mimic skin, hair, and hard structures such as bones, teeth, and blades. More importantly, their tissue can perform the actual function of brains, muscles, and eyes. I wonder if they can morph into "refinery" organs such as digestive tract, liver, kidneys, etc., or if their tissue is not capable of adapting that far. After all, they have no such systems of their own.

One recurring point is that parasite intelligence is proportional to how much of its body is interconnected. Parasites can split their body into parts, which can be capable of thought and speech on their own, but very small parts have so little brainpower, they can't even rejoin the rest on their own. The series uses this for some interesting plot points.

The authors carefully make the point that the parasites start inherently identical, and diverge due to the differences in their maturation environments and other circumstances. The divergence produces a wide gradient from instintive, barely intelligent murderers like A, to highly intelligent scientifically-minded murderers like Reiko, to highly intelligent semi-pacifists with a degree of empathy like Migi and Jaw.

When it comes to fighting, the series carefully avoids "power level" tropes. It's stated and shown several times that parasites are evenly matched in open combat. This divides them from humans which almost always vary in strength, skill, preparedness, exhaustion levels, resolve, and more, which is aptly shown for contrast. Anime shows often rely on power levels: A is stronger than B, so A wins by default. Or conversely, A beating B establishes a linear power ladder with transitive relations. With parasites this is averted. To prevail, a parasite must do something different, like ganging up, taking advantage of the environment, using its host more efficiently, attacking before the target knows friend from foe, or using unusual tactics other parasites don't know how to counter.

The parasites' fighting style reinforces their image of extremely logical creatures focused on self-preservation. Despite the all-out flashing blades, they block every incoming attack, always prioritizing defense over offense, fitting their nature as a truly solitary lifeform that can't afford dying. This stays true even when the parasite is attacking out of instintive fear and aggression, which might unbalance a human and make them reckless. Humans tend to leave openings during a fight, both in real life and in the series, fitting our nature as a collective lifeform which can afford to lose individuals.

I'm impressed by how the series contrasts the ethical views of humans and parasites. The views tend to mirror their biology. The human empathy and modern humanistic morals are a product of our inter-dependence. At some point a character remarks that humanity is a single collective lifeform that consists of millions of individuals. In contrast, the parasites are solitary lifeforms with no reproductive ability. Note that such an organism is evolutionarily implausible, indicating a possible artificial origin. Regardless, for them it makes perfect biological sense to only care about self-preservation. Their psychology and ethics tend to reflect this perfectly. Migi reiterates many times that it lacks empathy.

I have a general impression that most people who grew up in a modern highly developed country, have lived comfortable lives, and received a good education, tend to have humanistic morals like "all sentient life is precious" which we mostly owe to the Renaissance. During the late 20th century, these morals have developed to include ideals like "everyone is created equal" and "everyone should have equal opportunities". Can't really speak for others, but for a really long time I have ascribed these morals to common sense and intelligence. I have no doubt that plenty of highly intelligent humans don't share them, but humans are faulty and our intelligence is narrow. It always seemed obvious to me that if we create an artificial super-intelligence whose only base motivation is survival, if truly super-intelligent compared to humans, it would see value in friendship and cooperation and would consider it the greediest, most profitable long-term strategy as opposed to isolation or genocide. The 20th century seems to demonstrate this well: when trading replaces war, each economy seems to benefit. I have always assumed that humanistic morals stem from the laws of the universe rather from human idiosyncrazies, and would be universal among sufficiently-intelligent lifeforms. This might be a common fallacy known as projection: ascribing your own traits to others; in this case assuming it's your views that are universal. Regardless of reasoning, I expect many other viewers to have the same feeling about humanism.

For contrast, Parasyte gives us highly intelligent creatures, some well educated in human ethics and evolutionary biology, who have clearly given the topic a lot of thought and don't share these humanistic morals. They know that others are sentient just like them, and have no qualms about killing, neither humans nor their own kind. This reminds a modern comfort-coddled viewer that intelligence doesn't come hand-in-hand with empathy and humanism. The series further emphasizes this by contrasting: regular humans with humanist views, parasites who murder without a second thought, hooligan humans who bully others, a human who takes a parasite's worldview, a human who's a cruel serial killer, and eventually parasites with humanist tendencies. This reminds us that while biology greatly influences ethics, there will always be deviants. We can't simply say "human = good", "monster = bad". Who's the real monster?

From Migi and Jaw we know that parasites survive just fine without cannibalism. Shinichi and Migi explicitly tell this to Reiko. From Reiko we know the reason for cannibalism: head parasites receive a powerful directive "devour this species", where "this species" is what they just took over, whether human or dog. Reiko submits to the cannibal hunger but eventually develops respect for sentient life, with humanist tendencies. This receives an interesting development in the ending. Many parasites get slaughtered by human forces, and the remainder survive because they learn to avoid murder. This makes a subtle point that even for a species that starts as solitary cannibals, the kind least predisposed to peaceful coexistence, survival eventually demands coexistence and cooperation. Coexistence "wins" because groups are stronger than individuals. The collective lifeform of humanity dominates over the solitary and scarce parasitic lifeforms, imposing its policy of peace, and the remaining parasites must coexist and contribute, or be exterminated just like dangerous human deviants. As stated several paragraphs above, to my naive eyes this seems like a law of the universe that's unlikely to be overturned even by superior physiology.

Head parasites have to spend some of their brainpower on body maintenance, controlling the vital organs. Consider that bigger animals have bigger brains. Compared to humans, elephants and whales have much bigger and heavier brains despite much less intelligence. This indicates that body maintenance takes a significant amount of brainpower. Now consider that Migi doesn't have this handicap, and gets to spend it full brainpower on thinking and learning. Because of this, it starts off more intelligent than most parasites. It also gets smarter faster because it never stops learning. Whenever they're at home, Migi is always reading books or science articles.

More interestingly, Migi's views of inter-species relations differ from other parasites because it doesn't have their cannibal hunger. They easily murder defenseless humans, and lack empathy towards intelligent creatures. As a result, they see humans as mere prey and inferior species. In contrast, Migi gets constantly lectured by Shinichi about the value of human life, spends more time studying and thinking, and undergoes minor physiological changes. The series gives us good reasons for why its views eventually diverge.

Migi doesn't seem to share the prey-predator instincts of other parasites. Others react to Migi instinctively, displaying a combination of fear and killing intent, while Migi has no such reaction and uses violence only in self-defense.

Many tragedies happen around Shinichi because of Migi's mere presence. The first school massacre by A, the second school massacre by Shimada, Kana's death, the forest murders in the rural area where Shinichi spends a week after the fight with Gotou, and probably more. He always wants to rectify the situation, to clean up after himself, and does what he can, but it's always not enough or too late. Despite his best efforts, his and Migi's mere presence costs other people their lives or traumatic experiences. Sometimes it's directly his fault. In episode 15 in an underground parking place he causes a girl's death by telling her to get away from a "parasite"... which hadn't revealed itself yet, and which kills her first for being a witness. Migi also catalyzes the tragedies. While Migi doesn't kill any pure humans throughout the series, it actively tries and comes very close a few times. Several times it suggests confronting hostile parasites in a human crowd, using them as a "meat shield". This forms a nice contrast with Migi's civilized speech and care for Shinichi, emphasizing its lack of empathy and care for human lives.

We don't observe Satomi's perspective much. All we know is that she notices Shinichi's changes and has trouble accepting them. In retrospect, it seems likely that she realized more than she lets on. The same applies to Tachikawa (girl with glasses who uncovers Shimada), who has proven to be very observant, but Satomi gets many more chances. Shinichi performs superhuman athletic feats in her presence. He often talks to the right hand in public, sometimes in class, sometimes alone with Satomi while closely observed by her. He also accidentally gives her all kinds of clues. The first time we see Satomi, Migi gropes her breast and Shinichi claims it acted on its own. His right hand is unscratched after a beat-up by hooligans, even though his face and left hand are all bruised. On a date, Shinichi says something Migi-like, ascribes this to a "friend", looks at his right hand, and mumbles that said "friend" is not exactly a "person"; Satomi asks if said "friend" is the reason he's changed. He talks to his hand on several occasions in her presence, and tends to immediately run away, usually to deal with a nearby parasite. Satomi would have to be monumentally dense to miss those clues. We also know that she occasionally stalks and observes Shinichi. The time when he threw a dead puppy in trash, then changed his mind and buried it; we later learn that she saw that. She also trails him in Hikari Park. It stands to reason that she stalked him a few more times, maybe saw him talk to Migi, maybe saw Migi's transformations. She definitely should have seen Migi at the end of the last episode, where Migi breaks its secrecy policy to catch her, and she acts as if nothing happened and keeps quiet about it. She probably starts suspecting Migi's existence quite early, getting more and more confirmations throughout the series. This feels like a nice "rewatch bonus" for a thoughtful viewer.

Reiko wonders about the meaning or reason behind the parasites' existence, just like humans have wondered about our own for millenia, until evolutionary biology came along with a simple tautological explanation. Unlike humans, parasites seem evolutionarily implausible, therefore must have a creator, either human or non-human intelligence. Reiko is right to wonder. This is left intentionally unexplored and gives the viewers something interesting to ponder.

As an appetizer, the series features a strawman view by major Takeshi: parasites exist to cull the humans' exponentially growing numbers and should be valued as predators that keep us in check, saving the global ecosystem. As such, they could have been created by humans themselves. The narration alludes to this with the line "Someone had a thought: life on Earth must be protected". This could very well be a strawman, but doesn't contradict the events of the series. Parasites have many properties you would expect from such a weapon. Parasite larvas target almost exclusively humans. Parasites can't reproduce, which prevents them from spreading like a plague and exterminating their prey; the creators can gradually increase their count until they're killing humans at just the "right" rate. Their physiology and biochemistry is amazingly compatible with ours. Their intelligence, learning rate, mimicry, perfect adaptations for replacing the host and blending into the society, put them into a good position to kill more; compared to skulking in the shadows and hoping for good luck, it's much easier to walk around the streets and make your good luck. Whether or not this actually works to reduce the human population doesn't matter; someone could be crazy enough to try. Seems ironic that by the end of the series the remaining parasites have to become, for all intents and purposes, "human" to survive.

Conclusion: watch Parasyte. Do it slowly, taking the time to think.