Shin-Aomori is the northern terminus of the Tōhoku Shinkansen.
Underneath & a right angles to the Shinkansen station is the (narrow gauge) Ōu Main Line, which host a variety of trains, including the ones filmed here.
This video taken on 31 December 2014, prior to the opening of the Hokkaido Shinkansen.
0953 hrs: Tsugaru #4, 0951hrs ex Aomori, departs for Akita, with E751 series set #A102
1014 hrs: Super Hakucho #16, 0808hrs ex Hakodate, arrives at Shin-Aomori, with an 8 car 789 series EMU, including sets HE105 & HE201
1017 hrs: Super Hakucho #1 departs Shin-Aomori for Aomori (reverse) & Hakodate, with with series 785 set #NE303 leading a 6 car 789 series
1329 hrs: Resort Shirakami #1, 0828hrs ex Akita departs for Aomori, with 4 car KiHa 48 series set “Buna” (Japanese Beech)
AloJapan.com