White Blood Cell 8787 serves as a neutrophil defending an unhealthy human body suffering from poor maintenance and harsh conditions, primarily combating pathogens and infections. She has short purple hair and purple eyes. Her uniform includes a white blood cell cap, a loose coat-like top worn without garments underneath, white pants, sneakers, and fingerless black MMA gloves. She wields a katana as her primary weapon.

She operates alongside fellow neutrophils U-1196 and U-1212. 8787 is junior to U-1196 and works closely with her. She shares a close friendship with U-1212, and the two are constant companions on patrol and in combat.

During a state of bodily arousal, 8787 was deployed with others to the male reproductive organ to assist red blood cells in triggering an erection. This mission escalated when an infection by *Neisseria gonorrhoeae* occurred, forcing her and fellow neutrophils to fight the invading bacteria despite being outnumbered and depleted.