Gan Takada, alias Gan-chan or Yatterman-1, is the 13-year-old son of a toymaker who emerges as a heroic figure. He perfected his father's unfinished dog-shaped rescue robot Yatter-Wan, transforming it into a crime-fighting machine. Alongside his girlfriend Ai Kaminari (Yatterman-2), he battles the Doronbo gang's quest to assemble Skull Stone fragments for treasure.

In civilian life, he dons a blue jumpsuit and cap, reversing it to white while adding a red mask, black hat, and gloves as Yatterman-1. His signature weapon is the "Kenda-Magic," a modified kendama functioning as a flail, grappling hook, or electrified tool. He sporadically employs gadgets like the spinning top "Karu Koma" or beam cutter "Shuru Shuru Cutter."

The 1977 series depicts him as impulsively just with little mercy for villains. The 2008 remake initially presents him as lazy and needing Ai's motivation, though he matures into a responsibility-driven hero mirroring his original self. His partnership with Ai evolves into romance; they marry in "Time Bokan: Royal Revival," briefly ignoring the Doronbo gang during their honeymoon.

In "Yatterman Night," Gan and Ai are deceased, killed by the Skull Stone entity Dokurobei (later "Lord Yatterman"). Their legacy is exploited via robotic clones in the oppressive Yatter Kingdom, prompting Doronbo descendant Galina to adopt Gan's Yatterman-1 mantle.

He pilots mechas including Yatter-Wan, deploying miniature animal robots for combat, alongside aerial unit Yatter-Pelican and aquatic Yatter-Angler. After Yatter-Wan's destruction, he rebuilds it as the enhanced Yatter-King, equipped with firehose tails and projectile launchers.

In crossovers like "Tatsunoko vs. Capcom," he fights alongside Yatter-Wan using rapid ranged attacks despite low durability. His endings feature recruiting Capcom allies as auxiliary Yattermen or reuniting romantically with Ai.