is one piece episode 5 filler?

The girl introduces herself as Nami, a thief targeting and stealing from pirates. After collaborating with Luffy to escape from the Buggy Pirates, they find refuge at a restaurant, where Nami reveals her goal of collecting 100 million Berries for an unknown cause.

She then goes on and reveals her navigation skills. Nami betrays Luffy, tying him up and handing him over to the Buggy Pirates as a gesture of good will.

Buggy accepts, locks Luffy into a cage, and prepares a Buggy Ball, a powerful, explosive cannonball.