Nami serves as navigator for the Straw Hat Pirates during the special "Open Upon the Great Sea! A Father's Huge, HUGE Dream!". Her expert skills guide the crew to the treasure hunt island. Discovering the hidden treasure sparks immediate excitement, showcasing her signature enthusiasm for valuable finds.

She actively joins the crew's mission against the Bayan Pirates, fighting to free captured children and defeat their foes. Nami witnesses Bayan deploy a hypnotic choir that controls individuals, compelling Amanda to reveal her map tattoo and turning Luffy against his own crewmates.

After Usopp shatters the hypnotic choir's effect, Nami participates in the Straw Hats' unified assault that overwhelms Bayan. A distinct moment depicts Nami briefly wearing Luffy's iconic straw hat. The special also features Robin attempting her "Clutch" technique on the mind-controlled Luffy; the attack fails against his rubber body, forcing Robin to abandon it swiftly.