noun
Ueno-Tokyo Line
A JR East railway line connecting Ueno and Tokyo stations, providing through service to the Tōkaidō and Utsunomiya/Takasaki lines.
上野東京ラインで東京駅まで一本で行けます。
You can go directly to Tokyo Station on the Ueno-Tokyo Line.
Compound of 上野 (Ueno) + 東京 (Tokyo) + ライン (line). Named after the two major stations it connects.