Apex domains cannot have CNAME records.
Question and response
Question
dig 0.116.190.210.in-addr.arpa. NS
Answer
0.116.190.210.in-addr.arpa. 4 NS dns1.kessai.info.
0.116.190.210.in-addr.arpa. 4 NS ns-kg022.ocn.ad.jp.
Authority
The response has no authority records.
Additional
dns1.kessai.info. 4 A 210.190.116.101
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0