Apex domains cannot have CNAME records.
Question and response
Question
dig etius.jp. NS
Answer
etius.jp. 4 NS ns3.sphere.ad.jp.
etius.jp. 4 NS ns4.sphere.ad.jp.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0