To get to Nakano ZERO, exit the South Exit ticket gate of Nakano Station and walk along the tracks on the left, next to the Nakano Station Police Box.
Walk for about 8 minutes, and you'll see Nakano ZERO on your right.
Nakano ZERO is divided into the West Building and the Main Building. Behind the West Building, there's Koyo-yama Park, where a steam locomotive (C11 368) is on display.
Enter through the automatic doors of the West Building, near the park, and go up the stairs to the mezzanine, where there's a seating area.
There are circular wooden chairs, and about 5 people can sit there.
When I checked around noon on a weekday, there was only one person using it.
It may be crowded when cultural classes are held.
It's also famous for having a planetarium in the West Building, which has been showing since it opened in 1972. You can relax in the retro planetarium.
So, why not use it as a rest area where you can sit down around Nakano Station?