Kana Hanazawa as Red Blood Cell AE3803 (Erythrocyte) (voice)

Tomoaki Maeno as White Blood Cell U-1146 (Neutrophil) (voice)

Akira Ishida as Cancer Cell (voice)

Saori Hayami as Regulatory T Cell (voice)

Daisuke Ono as Killer T Cell (voice) / Memory T Cell (voice)

Toa Yukinari as NK Cell (voice)

Kikuko Inoue as Macrophage (voice)

Maria Naganawa as Platelet 'Leader' (voice)

Yusuke Kobayashi as Ordinary Cell (voice)

Yu-ri Yoshida as Black Lactic Acid Bacterium (voice)

Rie Takahashi as Red Lactic Acid Bacterium (voice)

Natsumi Fujiwara as Panda Lactic Acid Bacterium (voice)

Yurika Kubo as Dappled Lactic Acid Bacterium (voice)

Mamiko Noto as Narrator (voice)