Comparisons
I am not new to science fiction. I love the genre a lot. While Parasyte is incredibly unique, there are parts of it that reminded me of some of my other favorite series, and Reiko reminded me of some of my very favorite characters. I decided to draw comparisons to a couple here for fun. Obviously, there are spoilers for the series the characters come from, so read with caution. Both series have ended, but I really recommend them both.
Aftran 942 from Animorphs
I absolutely loved Aftran when she entered the series in book 19, The Departure. She was only in two books, but she brought a lot of depth to the series. She was a yeerk, which was a parasitic species that took over other species much like the parasites do in Parasyte, but she chose not to control other species. She felt it was wrong. She started the Yeerk Peace Movement with yeerks who didn't want to dominate their hosts.
I immediately thought of Animorphs when I first read the synopsis for Parasyte. They're both series about how humans deal with an invasion of parasites, and just like in Animorphs, you can't tell which humans are parasites in Parasyte (unless you're a parasite yourself, of course). In particular, Reiko really made me think of Aftran. They're both humanity's enemy, both fight for a way to coexist with humans, and it can be argued that they both feel what their species does to humans is wrong. They both sacrifice things that come natural to them to help out humanity. For Reiko, it's eating humans. For Aftran, it's controlling them. She chose to live her life as a blind and deaf slug, never able to experience again the beauty of the world, so that a human could be free.
Sharon “Athena” Agathon from Battlestar Galactica
Athena is one of my favorite characters in Battlestar Galactica. She is a cylon, which isn't a parasite, but a species (I guess you can call them that. They‘re machines.) that was fighting against humanity. She falls in love with a human and betrays the cylons for humanity. Even though she's a machine, she feels very human emotions, and chooses to live her life like a human. She eventually gives birth to the first human-cylon baby.
The number of things Athena and Reiko have in common blows my mind. They're both considered enemies of humanity in the beginning, they both think and feel human-like, they both betray their people, they both have a baby… Needless to say, after loving Athena for about a year now, Reiko's character really excited me.