"Clothing resembles the gi Goku wore when training with Whis in Dragon Ball Z: Resurrection ‘F’."
The Whis Symbol Gi's design is partially based on Goku's Turtle School Uniform though is a somewhat lighter shade of orange, lacks an inner shirt, and features a different styled obi, boots and wristbands. Though originally created by Whis the gi initially lacked a kanji, but while sparring with Goku and Vegeta on Beerus' Planet, Whis playfully signed the front of the gi with his symbol showing off his superior speed.
Goku also wore this gi during the Tournament of Destroyers in Dragon Ball Super. After the competition, Goku returned to wearing his regular outfit.
Video Game Appearances
In Dragon Ball Xenoverse 2, the Whis Symbol Gi returns as clothing options for the Future Warrior which can be obtained by transferring it over from Xenoverse or its pieces can be obtained in Parallel Quest 76: "Eternal Rival". Due to the lack of an inner shirt, a bra-like top appears when it is worn by females in both games.
In the Prison Planet Saga of Dragon Ball Heroes, Goku wears a variation of the Whis Symbol Gi that features his signature dark blue short-sleeved undershirt (with slightly-longer sleeves); an obi with the knot over the front of his waist rather than the side; and the Capsule Corporation's CC logo instead of Whis' symbol. Goku also wears this variation of the uniform in the anime adaptation of Dragon Ball Heroes.