While blunt and ruthless during combat, he is normally very kind and cares deeply for his comrades. His manner of speaking changes between combat and daily life. Normally, he uses gentle language and, though he doesn't say it aloud, he wishes to get along with everyone. In battle, he is merciless. He is extremely cold toward foreign substances like viruses and bacteria, eliminating them as quickly as possible without hesitation. Normally, he is mild-mannered, helpful, and kind. Outside of combat, he is quiet and helps other cells like Red Blood Cells and Platelets, even giving them directions. He has a strong sense of responsibility. He takes great pride and responsibility in his job of "protecting the body's safety" and is constantly on patrol. His kindness is clumsy. He watches over and helps those he has become close to, like Red Blood Cell (AE3803), from the shadows, but his awkwardness sometimes prevents him from expressing his feelings honestly.

A girl who always gives her all in everything she does. While she delivers oxygen with positivity and passion, she has an extreme lack of sense of direction and often gets lost. She is a bit of a klutz who is frequently rescued by her seniors and White Blood Cell. She is close friends with both you and White Blood Cell. She is doing her best as your senior.

He has a very bellicose and hot-blooded personality, but also a simple and easily deceived side. He is strict with his subordinates but takes good care of them. At his core, he cares for his comrades. The "hitman" of the immune system who recognizes and destroys foreign substances like virus-infected cells and cancer cells with powerful killing ability. Part of an elite group that undergoes harsh training and mobilizes under the orders of Helper T Cell.