Like A Dragon: Gaiden - Easy 3rd King Justice Win (No Heat Spam, No DLC)

Don't use Kiryu as your main. Level up your characters using the final platinum tournament challenge or buying level up items at fighters lounge if you struggle with the challenge, (can do easier challenge first to get a few levels if that helps). Done with 20 seconds to spare, also have done it with 1 minute to spare with exact same setup but didn't manage to get full recording of that.