Fifa 23 J League Mod [better] Guide
Launch the game through the Mod Manager. Go to Customize > Profile > Load Squads. You must load the custom squad file provided by the mod creator (usually a .json or .squads file). This contains the real player names and transfers.
Here is what the mod typically delivers (depending on the version, such as the popular FIFA Infinity or EEP patches): Fifa 23 J League Mod