White Blood Cell U-8787 operates as a neutrophil within a severely unhealthy and deteriorating human body suffering from abusive working conditions. She serves in the immune defense force, specializing in combating pathogenic threats alongside fellow neutrophils U-1196 and U-1212. Her duties include patrolling the body's systems and engaging invasive bacteria in direct combat.

U-8787 possesses short purple hair reaching her ears, matching purple eyes, and pale skin. She wears the standard neutrophil uniform: a white cap, a loose coat-like garment worn without an undershirt, white pants, sneakers, and fingerless black mixed martial arts gloves. She wields a katana as her primary weapon against pathogens.

Her operational context involves critical immune responses under strenuous conditions, such as defending the urethral region against Neisseria Gonorrhoeae. During this incident, overwhelming bacterial proliferation forced her and other neutrophils into a tactical retreat to a lymph node before counterattacking with antibiotic support. U-8787 and her colleagues face unwarranted blame from fellow cells, including red blood cells, for the body's weakened state despite their relentless efforts against escalating infections.

Her actions are integral to depicting the neutrophil division's collective struggle within the narrative framework, emphasizing the relentless challenges faced by immune cells in this compromised host environment.