It was given to him by the Dojo master in the Saffron City as a reward after Red won to the Dojo Master in a Pokémon Battle.
Hitmonlee fought against Giovanni's Rhyhorn, which already defeated four of Red's Pokémon. Hitmonlee used its Mega Kick, Rolling Kick and High Jump Kick in order to defeat Rhyhorn. It eventually defeated Rhyhorn but Hitmonlee was unable to fight any further aswell.
|Rolling Kick||File 3 - Giovanni|
|High Jump Kick||File 3 - Giovanni|
|Mega Kick||File 3 - Giovanni|
|+ indicates this Pokémon used this move recently.*|
- indicates this Pokémon normally can't use this move.