A filler arc set after Goat Island Arc and before the Jaya Arc. After evading some Marines, the crew stop off in a small town with a huge tower, which is also being oppressed by the Mayor whose overtaxing the citizens. But a bigger concern is a nearby mist that prevents anyone who enters it from leaving.
Rainbow Mist Arc
has the following tropes
- Big Bad: Wetton
- Chekhov's Gun: The tower.
- Foreshadowing: The marine captains that chase the Straw Hats in the beginning.
- Identical Grandson: Wetton's son and gradson, Flip and Lake, look very much like him was younger.
- Timey-Wimey Ball: The Pumpkin Pirates who are kids (save Henzo) through most of the arc as they were trapped in the Rainbow Mist though to them seemed like they were trapped for days when it was really years. At the end of the arc, they sacrifice themselves to help the Merry Go escape. But were blasted further back in time. They were picked up by a Marine ship and have been with them ever since. Growing up and working up the ranks, until they finally meet with the Straw Hats again only now much older.
- Year Outside, Hour Inside: How the Rainbow Mist works.