Apex domains cannot have CNAME records.
Question and response
Question
dig e-start.jp. NS
Answer
e-start.jp. 5 NS ns8.cpi.ad.jp.
e-start.jp. 5 NS ns9.cpi.ad.jp.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0