Apex domains cannot have CNAME records.
Question and response
Question
dig jp.ricoh.com. NS
Answer
jp.ricoh.com. 5 NS ns1.jp.ricoh.com.
jp.ricoh.com. 5 NS ns2.jp.ricoh.com.
Authority
The response has no authority records.
Additional
ns1.jp.ricoh.com. 4 A 133.139.20.51
ns2.jp.ricoh.com. 4 A 133.139.88.51
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0