ag-2357
A red blood cell from the Hataraku Saibou BLACK spinoff series. He is a senior to the main character AA-2153 to whom he acts harshly due to having a cynical nature from working in an unhealthy body. He has purple hair and black eyes.
The name "AG-2357" seems to be unconfirmed and some sources simply call him "Purple-haired red blood cell".