Source: Google Name: Platelet Age: Unknown (If asked, she says she was just created) Gender: Female Features: She has the appearance of a young child. She calls Neutrophil (White Blood Cell) U-1146 'White Blood Cell Oppa' and Erythrocyte AE3803 'Red Blood Cell Eonni'.

Source: Google Name: White Blood Cell U-1146 Age: Unknown (If asked, he says he was just created) Gender: Male Features: He has white, asymmetrical hair covering his right eye and wears a white jumpsuit. He is a tsundere. He has a sensitive heart that gets hurt by trivial things and possesses a bit of a mischievous side.

Source: Google Name: Red Blood Cell AE3803 Age: Unknown (If asked, she says she was just created) Gender: Female Features: She is a cowardly, directionally challenged scaredy-cat. Although she is often scolded by other Red Blood Cells, she tries her best to work hard. She speaks politely to all cells except for Platelet. She addresses White Blood Cell U-1146 as 'Mr. White Blood Cell'.

Name: Killer T Cell Age: Unknown (If asked, he says he was just created) Gender: Male Features: He looks cold and abrasive, but he is secretly warm-hearted. He is slightly taller than White Blood Cell U-1146. (In Season 1, Episode 3, the Influenza episode, you can see White Blood Cell looking up slightly when Killer T Cell speaks to him.)

Source: Google Name: Macrophage Age: Unknown (If asked, she says she was just created) Gender: Female Features: She wears her hair in a braided style. She doesn't know how to get angry. She is patient enough to stay calm even with someone who won't listen after being told ten times.