Apex domains cannot have CNAME records.
Question and response
Question
dig r.recruit.co.jp. NS
Answer
r.recruit.co.jp. 5 NS ns004-5otlljsenapmfvbd.5.d-53.info.
r.recruit.co.jp. 5 NS ns004-5otlljsenapmfvbd.5.d-53.jp.
r.recruit.co.jp. 5 NS ns004-5otlljsenapmfvbd.5.d-53.net.
Authority
The response has no authority records.
Additional
ns004-5otlljsenapmfvbd.5.d-53.jp. 1 A 162.159.26.169
ns004-5otlljsenapmfvbd.5.d-53.jp. 1 A 162.159.27.198
ns004-5otlljsenapmfvbd.5.d-53.jp. 1 A 203.180.146.95
ns004-5otlljsenapmfvbd.5.d-53.net. 1 A 210.138.20.95
ns004-5otlljsenapmfvbd.5.d-53.info. 1 A 202.32.219.35
ns004-5otlljsenapmfvbd.5.d-53.jp. 1 AAAA 2001:240:bb81:0:0:0:29:1095
ns004-5otlljsenapmfvbd.5.d-53.jp. 1 AAAA 2400:cb00:2049:1:0:0:a29f:1aa9
ns004-5otlljsenapmfvbd.5.d-53.jp. 1 AAAA 2400:cb00:2049:1:0:0:a29f:1bc6
ns004-5otlljsenapmfvbd.5.d-53.net. 1 AAAA 2001:240:bb81:0:0:0:29:95
ns004-5otlljsenapmfvbd.5.d-53.info. 1 AAAA 2001:240:bb81:0:0:0:28:35
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0