Apex domains cannot have CNAME records.
Question and response
Question
dig dev.ja.net. NS
Answer
dev.ja.net. 5 NS hv1-extdns-004.inf.virt.ja.net.
dev.ja.net. 5 NS hv1-extdns-003.inf.virt.ja.net.
dev.ja.net. 5 NS ns2.ja.net.
dev.ja.net. 5 NS hv1-extdns-001.inf.virt.ja.net.
dev.ja.net. 5 NS hv1-extdns-002.inf.virt.ja.net.
Authority
The response has no authority records.
Additional
ns2.ja.net. 5 A 193.63.105.17
ns2.ja.net. 5 AAAA 2001:630:0:45:0:0:0:11
. 0 OPT ; payload 1232, xrcode 0, version 0, flags 0