Apex domains cannot have CNAME records.
Question and response
Question
dig kuzuya.net. NS
Answer
kuzuya.net. 5 NS ns-452.awsdns-56.com.
kuzuya.net. 5 NS ns-607.awsdns-11.net.
kuzuya.net. 5 NS ns-830.awsdns-39.net.
kuzuya.net. 5 NS ns-967.awsdns-56.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0