Apex domains cannot have CNAME records.
Question and response
Question
dig xsp.ne.jp. NS
Answer
xsp.ne.jp. 5 NS milkroad.magma.ad.jp.
xsp.ne.jp. 5 NS x1turbo.ims.jp.
Authority
The response has no authority records.
Additional
x1turbo.ims.jp. 5 A 202.210.190.99
milkroad.magma.ad.jp. 5 A 219.101.80.32
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0