Apex domains cannot have CNAME records.
Question and response
Question
dig irohanihatena.com. NS
Answer
irohanihatena.com. 5 NS ns1.irohanihatena.com.
irohanihatena.com. 5 NS ns2.irohanihatena.com.
Authority
The response has no authority records.
Additional
ns1.irohanihatena.com. 5 A 5.135.31.119
ns2.irohanihatena.com. 5 A 72.9.153.107
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0