Apex domains cannot have CNAME records.
Question and response
Question
dig m-urakami.com. NS
Answer
m-urakami.com. 2 NS ns-485.awsdns-60.com.
m-urakami.com. 2 NS ns-811.awsdns-37.net.
m-urakami.com. 2 NS ns-868.awsdns-44.net.
m-urakami.com. 2 NS ns-370.awsdns-46.com.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0