Go Eunchan (as Wikipedia puts it: this is a Korean name, the family name is Go)

 Celerity demon

 168 cm and thin

 Short, tom-boyish hair

 Warm dark-brown eyes

Eunchan is a sweet girl who has never believed that you should treat anyone differently just because you can. She is incredibly horrified by the mistreatment of humans by selfish  demons. While she wants to do all she can to help, Eunchan is still quite young by demon  standards to be taking on the world. Instead, she works at the mall until she's finished with college. She does a very good job at the coffe shop where she met Anna. As Eunchan puts it, every time Anna comes to the mall she tricks someone into buying her coffee. The two have a  longstanding battle of Anna trying to find something Eunchan can't make or at least can't  make taste good. So far it's 202 to 0 in favor of Eunchan.