1992 Omiya-Morioka started as Tohoku Shin-kansen.
1985 Exteded from Omiya to Ueno.
1991 Exteded from Ueno to Tokyo.
2010 Extended from Morioka to Shin-Aomori.
2016 Exteded to Shin-Hakodate-Hokuto fron Shin-Aomori as Hokkaio Shin-kansen.
https://blog.goo.ne.jp/mittchan_january/m/201710
https://blog.goo.ne.jp/mittchan_january/m/201711
It's fine !