is one piece episode 220 filler?

Robin is reading late at night while the others are sleeping. Suddenly, a mysterious figure appears in the ocean and plays an instrument resembling a seahorse.

Nami wakes up in the morning, but cannot recognize Robin. Luffy, Sanji, Usopp, and Chopper also wake up soon after, all of which are confused as to why they woke up on the ship; their memories were erased.

Usopp lies and says that he was a famous pirate, but his lie is seen through. The Straw Hats all meet at the deck and notice Chopper, wondering who he is.