According to a newspaper article (of the Sports Hochi?) sited by this tweet, JSF confirmed that Rika is indeed back in Japan.On another note:
According to this: https://twitter.com/himarasukaru/status/1472385966338088960?s=20
I read about Yuna Shiraiwa's coach change, but wasn't sure who's her current coach now. Here it confirms that Yuna is training with Takeshi Honda. So Coach Honda is currently working with: Satoko and Yuna (and sometimes Marin when she returns to Kansai to train.)
I also got to read that Rika might be back to Japan to train already, due to the quarantine requirement. But I didn't find the source so it's yet to be confirmed.