Apex domains cannot have CNAME records.
Question and response
Question
dig kodomonoegao.net. NS
Answer
kodomonoegao.net. 5 NS ns-1533.awsdns-63.org.
kodomonoegao.net. 5 NS ns-1305.awsdns-35.org.
kodomonoegao.net. 5 NS ns-1762.awsdns-28.co.uk.
kodomonoegao.net. 5 NS ns-1740.awsdns-25.co.uk.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0