Apex domains cannot have CNAME records.
Question and response
Question
dig kddi-web.com. NS
Answer
kddi-web.com. 4 NS ns4.cpi.ad.jp.
kddi-web.com. 4 NS ns5.cpi.ad.jp.
kddi-web.com. 4 NS ns2.cpi.ad.jp.
kddi-web.com. 4 NS ns7.cpi.ad.jp.
kddi-web.com. 4 NS ns0.cpi.ad.jp.
kddi-web.com. 4 NS ns1.cpi.ad.jp.
kddi-web.com. 4 NS ns6.cpi.ad.jp.
kddi-web.com. 4 NS ns3.cpi.ad.jp.
Authority
The response has no authority records.
Additional
ns0.cpi.ad.jp. 4 A 122.200.253.230
ns1.cpi.ad.jp. 4 A 122.200.212.130
ns2.cpi.ad.jp. 4 A 122.200.253.231
ns3.cpi.ad.jp. 4 A 122.200.212.131
ns4.cpi.ad.jp. 4 A 122.200.253.232
ns5.cpi.ad.jp. 4 A 122.200.212.132
ns6.cpi.ad.jp. 4 A 122.200.253.233
ns7.cpi.ad.jp. 4 A 122.200.212.133
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0