ps21.spcloud.jp has no CNAME records.
Question and response
Question
dig ps21.spcloud.jp. NS
Answer
The response has no answer records.
Authority
spcloud.jp. 349 SOA ns-1517.awsdns-61.org. awsdns-hostmaster.amazon.com. 1 7200 900 1209600 86400
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0