TV-Series
Description
U-1146 is a neutrophil operating in the human immune system, designated to patrol blood vessels and eliminate invading pathogens like bacteria and viruses. He maintains a reserved, aloof demeanor during routine duties but shifts into highly aggressive efficiency during combat. Despite his violent occupation, he consistently demonstrates kindness and selflessness—prioritizing the protection of all cells regardless of type, showing empathy toward infected cells he must destroy, and listening to adversaries such as Cancer Cell before their elimination. He extends particular care to younger or vulnerable cells, including Platelets and a specific Normal Cell he affectionately nicknames "Cell Boy."

His background traces to myelocyte training, where he encountered a young Red Blood Cell (AE3803) under attack by a Pseudomonas Aeruginosa bacterium. He shielded her and sustained injuries until reinforcements arrived. Before parting to their respective bone marrows, they expressed a desire to reunite as mature cells, though U-1146 did not initially recognize AE3803 after graduating as a full-fledged neutrophil.

Specialized abilities equip him for his role: phagocytosis for analyzing or consuming foreign cells, proficiency in close-quarters knife combat, and transmigration to move freely through tissues. His uniform incorporates an L-selectin mechanism for surface adhesion and a removable receptor functioning as a proximity radar.

The spin-off *Cells at Work! WHITE* expands his characterization into a leadership role within his neutrophil team, alongside subtle "emo subculture-esque" traits. In the live-action film adaptation, U-1146 operates within Niko Urushizaki’s body—a host supported by healthy habits—collaborating with cells like NK Cell and Killer T Cell during pathogen invasions. This narrative contrasts her father Shigeru’s unhealthy lifestyle, emphasizing the cells’ dedication to preserving their host’s life without exploring personal motivations beyond duty.

An earlier pilot chapter conceptualized him as White Blood Cell No. 1116, a macrophage with a less diligent work ethic and reluctance to confront threats like Cancer Cell. This iteration introduced a reincarnation mechanic for deceased cells, absent in the main series.