Although the official name was Hokuriku shinkansen, it was called Nagano shinkansen when it opened till Nagano station in 1997 to host winter Olympic games in Nagano 1998.
Nagano shinkansen used the same tracks from Tokyo station to Takasaki station in Gunma prefecture, then headed west. Before the shinkansen, limited express Asama was the role to connect the nation capital and the city of Nagano which was developed around Zenkoji temple.
Limited express Asama, which is named after Mt.Asama, which is a volcanic mountain in the region.
The limited express run on Shinetsu main line from Takasaki and had to pass the Usui Pass which was the one of the steepest railway passes in Japan. Therefore two electric locomotives had to be connected between Yokokawa and Karuizawa stations. Passengers had plenty of time to buy the ekiben(station sold meal box) at these stations due to the preparation and disconnection of the locomotives. The most favorite ekiben was TOGE NO KAMAMESHI(kettle rice of the Pass).
After opening of Nagano shinkansen, Shinetsu main line between Yokokawa and Karuizawa was abolished, bus connects the stations regularly. Shinkanse itself runs through a long tunnel after passing Annaka-Haruna station and reaches Karuizawa station. Therefore you can buy the Toge no kamameshi at Karuizawa station or on board.