1. watchA
https://www.training.jp http://www.training.jp
../training.co.jp はまともか。
2. whois
[Domain Name] TRAINING.JP [Registrant] JTS Corporation [Name Server] ns1.dns.ne.jp [Name Server] ns2.dns.ne.jp [Signing Key] [Created on] 2001/05/07 [Expires on] 2021/05/31 [Status] Active [Last Updated] 2020/06/01 01:05:09 (JST)
3. history
$ dig -t ns training.jp @ns1.dns.ne.jp ; <<>> DiG 9.11.3-1ubuntu1.12-Ubuntu <<>> -t ns training.jp @ns1.dns.ne.jp ;; global options: +cmd ;; Got answer: ;; ->>HEADER<<- opcode: QUERY, status: REFUSED, id: 27545 ;; flags: qr rd; QUERY: 1, ANSWER: 0, AUTHORITY: 0, ADDITIONAL: 1 ;; WARNING: recursion requested but not available ;; OPT PSEUDOSECTION: ; EDNS: version: 0, flags:; udp: 4096 ;; QUESTION SECTION: ;training.jp. IN NS ;; Query time: 18 msec ;; SERVER: 61.211.236.1#53(61.211.236.1) ;; WHEN: Sun Jan 17 10:17:15 JST 2021 ;; MSG SIZE rcvd: 40