Apex domains cannot have CNAME records.
Question and response
Question
dig otsuka-shokai.co.jp. NS
Answer
otsuka-shokai.co.jp. 4 NS ns5.otsuka-shokai.co.jp.
otsuka-shokai.co.jp. 4 NS ns1.otsuka-shokai.co.jp.
otsuka-shokai.co.jp. 4 NS ns3.otsuka-shokai.co.jp.
otsuka-shokai.co.jp. 4 NS dns102.dion.ne.jp.
Authority
The response has no authority records.
Additional
ns1.otsuka-shokai.co.jp. 4 A 157.205.233.250
ns3.otsuka-shokai.co.jp. 4 A 111.87.26.250
ns5.otsuka-shokai.co.jp. 4 A 157.205.232.119
ns1.otsuka-shokai.co.jp. 4 AAAA 2403:6c00:300b:e910:0:0:28:250
ns3.otsuka-shokai.co.jp. 4 AAAA 2001:268:806:100:0:0:36:250
ns5.otsuka-shokai.co.jp. 4 AAAA 2403:6c00:300a:e810:0:0:196:250
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0