The Mii Gunner's costume represents Ray Mk III, the upgraded robotic form of Ray Mk II, a "Ray" series Robo from the Custom Robo series.
The stage represents the Holosseums, an arena in the Custom Robo series featuring different layouts where Custom Robos engage in competitive battles.
The music track represents the musical theme of Chōsōjū Mecha MG, which features customizable battling robots similar to the Custom Robo series.
The Mii Gunner starting off with a Rocket Belt references the jetpack equipped to the Ray series' robotic armor, which allows them to fly and hover in midair.
The Mii Gunner's moveset references Ray Mk II's moveset in Custom Robo V2 which includes: Straight Bomb S (represented by Grenade Launch), Sniper Gun (represented by Stealth Burst), Ground Legs (represented by Lunar Launch), and Speed Pod P (represented by Bomb Drop).
