Apex domains cannot have CNAME records.
Question and response
Question
dig disney.jp. NS
Answer
disney.jp. 5 NS ns2.disneyinternational.net.
disney.jp. 5 NS ns1.disneyinternational.net.
disney.jp. 5 NS ns4.disneyinternational.net.
disney.jp. 5 NS ns3.disneyinternational.net.
Authority
The response has no authority records.
Additional
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0