Apex domains cannot have CNAME records.
Question and response
Question
dig besender.jp. NS
Answer
besender.jp. 5 NS ns-659.awsdns-18.net.
besender.jp. 5 NS ns-241.awsdns-30.com.
besender.jp. 5 NS ns-1843.awsdns-38.co.uk.
besender.jp. 5 NS ns-1496.awsdns-59.org.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0