Apex domains cannot have CNAME records.
Question and response
Question
dig itbridge.awk.jp. NS
Answer
itbridge.awk.jp. 5 NS ns01.xbit.jp.
itbridge.awk.jp. 5 NS ns.itbridge.awk.jp.
Authority
The response has no authority records.
Additional
ns.itbridge.awk.jp. 5 A 59.106.59.205
ns01.xbit.jp. 4 A 59.106.35.125
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0