nsb.dns.jp has no CNAME records.
Question and response
Question
dig nsb.dns.jp. NS
Answer
The response has no answer records.
Authority
dns.JP. 560 SOA z.dns.JP. root.dns.JP. 2025032601 3600 900 1814400 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0