Brief ass at the start of this December 2021 clip found on Twitter.
Actual ass shot on this show was a bit longer but I can't find the full episode free anywhere. In English the show title is "Shin'nichi-chan pion!" and Pieter has been on it about 4 times since late 2021 but only showed some ass the first time she was on as far as I know.
Edit: She was just on that show again and showed zero ass. Not surprising seeing how it's a New Japan based show and they have been lame as fuck in recent years with intentionally not showing her ass and it's annoying as hell. Don't waste your time watching it if you see it on any japanese tv sites.