Happy Gear

The Happy Gear is a Keychain for Sora's Keyblade in Kingdom Hearts III.

Design
Happy Gear's design is based on the machinery found in the Monsters, Inc. factory. The handle is based on the shaft that lowers doors into place, while the guard comprises two scare canisters. The base of the blade shows a door and the mechanism holding it in place. The blade itself is the long shaft that carries doors around the factory, with a claw serving as the teeth. A Monsters, Inc. worker's helmet is shown at the tip of the blade. The keychain is a simple black string, with Boo's monster disguise serving as the token.

The Keyblade's name is derived from how Monstropolis is powered by laughter, as well as the machinery that comprises the weapon. Early demo and press releases for Happy Gear called it "Smile Gear," which has a similar naming theme.

Other appearances
Various game retailers offered a special yo-yo inspired by the "Twin Yo-Yos" form change as a preorder bonus for Kingdom Hearts III.