Basophil

Basophil (好塩基球, Kōenkikyū) is a minor character in Cells at Work!

He is a type of white blood cell, specifically Basophil. He is capable of triggering the release histamines when encountering an antigen. He also can allure eosinophils and neutrophils when they are needed. His role is not fully discovered as he always remain mysterious.

Appearance
Befitting his enigmatic personality, most of his body is covered, leaving only the area around his eyes visible. He wears a rainjacket over what appears to be a knit cap and a balaclava and carries an umbrella around, likely for protection against stomach acid. What lies behind that mask of his may never be known...

Personality
Much like actual basophils, he remains a mysterious figure, often appearing to speak through philosophical and metaphorical language.

Trivia

 * Eosinophil is the only other cell shown to understand his style of speech, even interpreting for him in chapter 5 of the manga (episode 4 of the anime).
 * Despite being a white blood cell, he has not been shown participating in combat himself.