Apex domains cannot have CNAME records.
Question and response
Question
dig rakurakuhanbai.jp. NS
Answer
rakurakuhanbai.jp. 5 NS ns-846.awsdns-41.net.
rakurakuhanbai.jp. 5 NS ns-379.awsdns-47.com.
rakurakuhanbai.jp. 5 NS ns-2021.awsdns-60.co.uk.
rakurakuhanbai.jp. 5 NS ns-1349.awsdns-40.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0