Ep. 9: Killer T Cell disrupts Helper T Cell during a drill, revealing their shared past at Thymus School.

During a training exercise, Killer T Cell accidentally throws a trainee into Helper T Cell’s office, striking the commander. This incident sparks an argument between the two characters, who are described as polar opposites. Dendritic Cell explains that despite their current differing roles, they were once classmates at Thymus School. She further discloses how distinct their personalities were during their youth. The narrative highlights the intense and selective nature of their shared history, noting that only two to three percent of the class successfully graduates from the rigorous and hellish training days at the school.

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