Cells at Work! Wiki
Natural Killer Cell
 JAPANESE NAME ナチュラルキラー細胞
 ROMANJI Nachuraru Kirā Saibō
Petty Woman (by Killer T Cell)
 STATUS Active
 GENDER Female
 SPECIES Lymphocyte Cell
 OCCUPATION Infected Cells Identifier/Killer
 ANIME DEBUT Episode 6
 MANGA DEBUT Chapter 8
 JAPANESE Toa Yukinari
 ENGLISH Morgan Berry

Natural Killer Cell (ナチュラルキラー細胞, Nachuraru Kirā Saibō) is a minor character in Cells at Work!


She is a muscular and fit woman. Her short black hair is cut unevenly and covers her right eye. She wears a black tank top, green shorts, and boots. When she’s activated by Dendritic Cell her saber glows like a lightsaber and the blade turns purple


NK Cell is seemingly antagonistic and aggressive when it comes to her duties, as she will go as far as to threaten normal cells. At default, she is a rather sarcastic woman who prefers working independently, as she cares for her friends' safety.

She is rivals with Killer T Cell, as they are always bickering over who should complete the task and often brawl with each other. Due to this, she is easily amused when something comical happens to him.


She is a white blood cell, specifically a Lymphocyte (Natural Killer Cell). She is tasked to identify, track, and kill cancer cells, viruses, and infected cells by moving freely from tissue to tissue.



NK Cell has heightened senses compared to other lymphocytes, and it is her task to detect disguised or hidden infected cells and viruses.

  • Overall Abilities: She is extremely skilled at killing pathogenic cells. She can single-handedly finish the tasks of a few killer T cells. She is swift and strong and capable of breaking tissue walls during fights.
  • Saber Proficiency: She can professionally wield a sabre sword.
  • Cytotoxic: NK Cell can kill aberrant or normal cells under discretion.
  • Adaptive Memory: She can remember previous infected cells and their attack moves for easier termination in case one of them appears again in the future.
  • Transmigrate: She is able to move freely through tissues to reach her target faster.


  • Natural killer cells and killer T cells resembles brothers-in-arm because of their complementary roles for each other. This explains the close yet competitive relationship between NK Cell and Killer T Cell in the series.