TV-Series
Description
AA2153 commences his career as a rookie red blood cell transporter within a severely unhealthy body. Initial enthusiasm for his vital work swiftly collides with the body's harsh realities: pathways choked by cholesterol, pervasive carbon monoxide, and dangerous encounters with pathogens like pneumococcus. These relentless challenges breed significant stress and disheartenment.

His appearance features brown hair, glasses revealing yellow pupils, and the standard red blood cell uniform. A distinct ahoge-like strand of hair is present. His cell code, AA2153, is marked on the back of his hat, typically remaining unseen.

His personality evolves through critical experiences. Early on, he exhibits unwavering dedication to his role despite the abusive environment. He forms a close bond with fellow erythrocyte AC1677, a companion from bone marrow school, and neutrophil U-1196, who often rescues him and offers encouragement. The death of AC1677 during a stomach ulcer incident deeply scars him, triggering intense survivor's guilt. This precipitates a depressive collapse where he abandons his duties and seeks processing in the spleen, only to be denied due to his physical condition.

Later, amid a gout attack, a crisis of faith erupts. He rebels against the body, violently assaulting a urate crystal with a pipe and his bare hands while screaming at the host to adopt healthier habits. U-1196 intervenes, offering a calming embrace and reassurance that AC1677's death was not his fault. This pivotal moment helps him confront his grief and survivor's guilt, enabling his return to work with renewed determination. Following the body's recovery from a heart attack and the host's improved lifestyle, his outlook shifts towards optimism and resolve.

Transfused into a new, even unhealthier body, he faces scorn from local erythrocytes for his persistent optimism. Despite worsening conditions and further losses, he actively encourages fellow cells to persevere. In this new environment, he is repeatedly saved by neutrophil J-1178, whom he nicknames "White Blood Cell-chan." His steadfastness evolves into a leadership role among the erythrocytes.

Throughout his journey, he displays a strong tendency to overwork, driven by a sense of responsibility and a desire to enhance conditions for others. This necessitates reminders from figures like AC1677 and U-1196 that sustaining the body is a collective effort. His core abilities center on efficiently transporting oxygen, carbon dioxide, and nutrients, adeptly navigating constricted spaces, and enduring long periods carrying heavy loads.

Central relationships shaping his development include his mentorship of younger red blood cells, his profound bond with AC1677, his reliance on U-1196 for emotional support and protection, and his eventual role as an inspiration to jaded cells in the second body. Occasional ship tease with U-1196 is implied, including moments suggesting romantic feelings towards her.

Notable trivia includes a work enthusiasm rating of 10, a physique score of 71/100 assessed by the elder glomerulus, and an original character design concept for red hair later changed to brown.