What is the One Piece's "Episode of Nami" categorized as? The One Piece's "Episode of Nami" is not an anime episode because of its length. What is that episode categorized as?
Episode of Nami: Tears of a Navigator and the Bonds of Friends is a TV Special of the One Piece anime. It aired after Episode 560. 


(From the One Piece wiki Episode of Nami)

It is the 5th TV special to be aired. The list of TV specials so far:


Adventure in the Ocean's Navel
Open Upon the Great Sea! A Father's Huge, HUGE Dream!
"Protect! The Last Great Performance"
The Detective Memoirs of Chief Straw Hat Luffy
Episode of Nami: Tears of a Navigator and the Bonds of Friends
Episode of Luffy: Adventure on Hand Island