Apex domains cannot have CNAME records.
Question and response
Question
dig cn-0002.jp. NS
Answer
cn-0002.jp. 1 NS dns2.cn-0002.jp.
cn-0002.jp. 1 NS dns1.cn-0002.jp.
Authority
The response has no authority records.
Additional
dns1.cn-0002.jp. 1 A 59.106.32.195
dns2.cn-0002.jp. 1 A 158.210.243.74
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0