Piyoko and Coo are fictional character from the anime/manga series "Di Gi Charat". These two are very close childhood friends. Piyoko, a blonde panda-girl who ends her sentences with "pyo", is a young princess of a planet known as Analogue. Coo, a dog-boy, is one of three whose duty it is to protect her.
"Answer" is a Coo character song.