rspdns.jp を whois.jprs.jp にて検索しました:

[ JPRS database provides information on network administration. Its use is    ]
[ restricted to network administration purposes. For further information,     ]
[ use 'whois -h whois.jprs.jp help'. To suppress Japanese output, add'/e'     ]
[ at the end of command, e.g. 'whois -h whois.jprs.jp xxx/e'.                 ]
Domain Information: [ドメイン情報]
[Domain Name]                   RSPDNS.JP
[登録者名]                      ＲＳＰインターネットグループ
[Registrant]                    RSP Internet, Group.
[Name Server]                   ns2-cf.rspnet.jp
[Name Server]                   ns1-cf.rspnet.jp
[Signing Key]
[登録年月日]                    2023/01/15
[有効期限]                      2025/01/31
[状態]                          Active
[ロック状態]                    DomainTransferLocked
[ロック状態]                    AgentChangeLocked
[最終更新]                      2024/04/09 10:17:08 (JST)
Contact Information: [公開連絡窓口]
[名前]                          ＲＳＰインターネットグループ
[Name]                          RSP Internet, Group.
[Email]                         rikusutep@o.rspnet.jp
[Web Page]
[郵便番号]
[住所]
[Postal Address]
[電話番号]                      +81.298286480
[FAX番号]