According to the company, the first private shinkansen compartments were introduced in 1985 in its 100 Series trains, which were discontinued in 2003. Double-decker 200 Series train cars used for the Tohoku Shinkansen line also featured private rooms. Currently, the four-person compartments in the Sanyo Shinkansen's 700 Series cars are the closest thing to private rooms available on a Japanese bullet train. The company explained, "We have been studying new seating arrangements for bullet trains to meet customers' needs, which are diversifying due to changes in life- and work styles." These had included plans for seating that creates an enhanced business environment and higher-class seats in Green Cars that allow passengers to pass their travel time in comfort.