The Fediverse
Do you use the Fediverse (Pleroma, Mastodon, or Misskey)? All three platforms use the same protocol, ActivityPub, so you can easily communicate with users on Misskey even if you're on Pleroma, for example. Misskey is a Japanese technology, which is pretty fascinating on its own. It seems that nearly everyone using it is Japanese.
After Elon Musk bought the anti-social media network Twitter, rebranded it as "Ex-Twitter," and turned it into a platform spreading falsehoods, hatred, and unreason, millions of people joined the Fediverse in protest.
I have a Pleroma account that I use to post about Japan. If you're interested in exploring the Fediverse, register an account and let's talk about Japan and language learning!
Some Pleroma instances for new users: