Erythroblast is a supporting character in the anime series 'Hataraku Saibou' (Cells at Work!). She is depicted as a developing red blood cell still in her immature form, known as an erythroblast. Erythroblast is responsible for learning the functions and responsibilities of a mature red blood cell, such as oxygen transport. Her role in the series is to represent the early stages of red blood cell development, often shown undergoing training and guidance from more experienced cells, highlighting the growth and maturation process within the body.