is one piece episode 406 filler?

Usopp visits The Pinwheel to tell Onami, Sanji, Luffy and Chopper about the upcoming Mikoshi (portable shrine) race, which takes place every 100 years and has the grand prize of a sacred treasure that will supposedly grant any wish and 1,000,000. Usopp also meets Mao, a new employee hired by Onami.

In order to enter as the Pinwheel Eatery team, Luffy, Usopp Onami and Chopper visit Franky, the greatest builder in Grand Jipangu, and are introduced when Franky's clockwork drying mechanism accidentally flings his loincloth into Onami's face.