Haien Kyuukin is a strong enemy in the Cells at Work! series. He appears as a dangerous pathogen that can attack the lungs, destroy red blood cells, and even threaten the brain. With a scary, villain-like look and sharp claws, Haien Kyuukin tries to steal nutrients from the red blood cells. He is known for his sneaky tricks and battles fiercely with Neutrophil. He first shows up in Episode 1 and has also appeared in several other spin-off works, where he is shown as a monster that frightens the body’s defenses. He even has a “big brother” who helps other villains. Haien Kyuukin stands out because of his purple color, which comes from real-life science.
Haien Kyuukin is shaped like a human but looks otherworldly.
His skin is light purple, and he has clawed hands and movable antennae on his head.
These sharp claws and long appendages are used to attack his enemies.
He also wears a capsule-like shell that can act as a shield.
He acts like a typical villain in a superhero show.
Haien Kyuukin is cunning and sometimes arrogant.
He likes to trick his opponents and tries to outsmart them.
Haien Kyuukin represents a real type of bacteria that can cause serious pneumonia and other infections in humans.
His purple color is based on how the actual bacteria look when dyed in a lab test called the Gram stain.
Haien Kyuukin can break into the alveoli (the tiny sacs in the lungs) and attack red blood cells.
He can use poison to melt and eat red blood cells.
His sharp claws and stretching antennae allow him to fight both up close and from a distance.
He uses his capsule-like shell to block attacks and escape.
Haien Kyuukin has a brother, who also appears in the story.
He sometimes teams up with other villain bacteria, like Kiiro Budou Kyuukin (Staphylococcus Aureus).
Other bacteria sometimes make fun of him for not being careful enough.
Haien Kyuukin is colored purple because, in real science, his bacteria type appears purple after a special staining test (Gram positive).
He is one of the few villains who manages to seriously threaten or even hurt Erythrocyte in the main story.
He is shown in many spin-off series and is often even scarier there.
In the anime, he talks, but in spin-offs like Cells at Work! BLACK and Cells at Work! LADY, he makes only monster-like noises and is even more terrifying.
"Honestly, what a bunch of fools."
First Appearance and Attack in the Lungs
Haien Kyuukin first appears in Episode 1, breaking through the blood vessel wall.
He and his group attack but are quickly defeated by Neutrophil and his team.
One Haien Kyuukin survives by hiding among Erythrocyte’s packages.
Inside the Lungs
This last Haien Kyuukin sneaks into the lungs.
He tries to attack Erythrocyte, hoping to eat her red blood cell nutrients.
Haien Kyuukin uses his capsule shell to defend himself and block attacks.
Battle with Neutrophil
Neutrophil notices Haien Kyuukin because of receptor signals.
A big fight happens, with Haien Kyuukin trying to trick and survive thanks to his shell.
But Erythrocyte and Neutrophil lure him into the airway.
He gets blown out of the body in a strong sneeze, called Sneeze #1.
Entry of Haien Kyuukin’s Brother
In Episode 2 (from Chapter 4 in the manga), Haien Kyuukin’s brother appears, working for Kiiro Budou Kyuukin.
He is mad at his brother for being careless, but he also gets defeated by Neutrophil right after.
Appearances in Spin-Offs
Haien Kyuukin shows up in the first episodes of spin-off series like Cells at Work! BLACK and Cells at Work! LADY.
In these, he acts even more monstrous and does not speak.
Instead, he attacks and eats red blood cells in a very scary way.
Haien Kyuukin is inspired by a real danger to human bodies, making him an important villain in the Cells at Work! universe.
His many appearances in different shows make him a memorable enemy.
💬 Community Discussion
Talk about this anime with people who actually care.