質問:日本語のマストドンコミュニティはありますか?

答え:日本のマストドンユーザー:mastodon.nil.nuは、今登録したいかもしれない日本語のサーバーです(2017年4月)。参加したい場所はどこでも歓迎ですが。 (Googleはこれを翻訳しました)

Question: Is there a Japanese-language Mastodon community?

Answer: Japanese Mastodon users: mastodon.nil.nu is a Japanese-language server you might want to register with for now (April, 2017). Though you're welcome anywhere you want to join. (Google translated this)

Q: How did Mastodon become so popular in Japan?

A: An exceptionally good article in "ASCII" magazine by Satoshi Endo, a long-time computer researcher in Japan, based in part on setting up and running his own Mastodon instance (8-p.net). That's a journalistic standard I'd like to see more in the West.
http://ascii.jp/elem/000/001/465/1465842/

@dredmorbius Except that it doesn't really answer that question does it? Unless the answer is 'the larger message size is useful for kanji users

nil.nuに所属していたユーザーがすべてmstdn.jp所属に変更された。ドメインが変わっただけで中身は同じ。たくさん日本人がいる。
Users whose domain name is "mastodon.nil.nu" have its name changed to "mstdn.jp". But its contents are the same.

See: https://mstdn.io/users/ym/updates/12761