2B and 9S are YoRHa units, sophisticated androids with white hair, blue-gray eyes, and black visors covering their eyes. 2B is a combat model who initially appears cold and reserved, but is deeply caring and loyal to those she trusts. 9S is a scanner model who seems shy and cute on the surface, but is more impulsive and can be surprisingly ruthless in his logic, questioning the nature of their machine enemies.