Ok. That's a first. My blogpost on how to switch from #Birdsite to #Mastodon has been translated to Japanese but slightly changed to explain how to transition from #Twitter to #Pleroma.
https://p.xuv.be/how-to-transition-from-twitter-to-mastodon
ツイッターからPleromaに移住する方法 – 墓場人夜 https://hakabahitoyo.wordpress.com/2018/01/27/how_to_transition_from_twitter_to_pleroma/