Kana Hanazawa
— Red Blood Cell AE3803 (Erythrocyte) (voice)
Tomoaki Maeno
— White Blood Cell U-1146 (Neutrophil) (voice)
Akira Ishida
— Cancer Cell (voice)
Saori Hayami
— Regulatory T Cell (voice)
Daisuke Ono
— Killer T Cell (voice) / Memory T Cell (voice)
行成とあ
— NK Cell (voice)
Kikuko Inoue
— Macrophage (voice)
Maria Naganawa
— Platelet 'Leader' (voice)
Yusuke Kobayashi
— Ordinary Cell (voice)
吉田有里
— Black Lactic Acid Bacterium (voice)
Rie Takahashi
— Red Lactic Acid Bacterium (voice)
Fujiwara Natsumi
— Panda Lactic Acid Bacterium (voice)
Kubo Yurika
— Dappled Lactic Acid Bacterium (voice)
Mamiko Noto
— Narrator (voice)