tsukaeru.jp.		30 IN SOA ns1.tsukaeru.net. admin.tsukaeru.net. (
				2020120402 ; serial
				7200       ; refresh (2 hours)
				3600       ; retry (1 hour)
				604800     ; expire (1 week)
				600        ; minimum (10 minutes)
				)

Name servers:
tsukaeru.jp.		30 IN NS ns2.tsukaeru.net.
tsukaeru.jp.		30 IN NS ns1.tsukaeru.net.