The Yonjōnagamitsu (四乗長光, "Quadruple Nagamitsu") is a sword formed by the Arms Microns Ex, Geki, Shou, and Go, meant to be wielded by the Swordbots in their combined forms. It is designed to be wielded in reverse-grip (IE, with the sword pointing down), and is often accompanied by the Arms Micron Sen attaching to the wielder as a jet booster.
- Ex (Promotional Arms Micron, 2013-11-16)
- Geki (Promotional Arms Micron, 2013-11-16)
- Shou (Promotional Arms Micron, 2013-11-16)
- Go (Promotional Arms Micron, 2013-11-16)
- The Yonjōnagamitsu is formed from the combination of the four promotional-giveaway Arms Microns listed above. Each component was only available as a free gift with the purchase of more than 3000 yen of Transformers: Go! toys at certain stores. Each Micron came unassembled on a runner, like a model kit.
- Nagamitsu was a famous sword smith from the Kamakura Period of Japan. Presumably, the sword is called a "Nagamitsu" in reference to the sword maker, who was known for making showier swords as well as more traditional ones.