Opo is the angel of water and is the guardian of Rho. Her protected one is Matrix.
Profession: Guardian Angel
Celestial Race: Archangel
Skin: Seafoam Green
Opo loves her protected one, Matrix, and has been known to appear on his shoulder in random places and talk to him. Of course, the people around him can't see Opo so he looks like a crazy person talking to himself.
Find out more about Opo in Volume 6.