Kanda River

Construction began in the 1980s of a diversion tunnel which could temporarily store excess water which historically has been a big problem causing flooding to thousands of homes during powerful typhoons or torrential downpours.

The Kanda River Underground Diversion Channel is actually one huge tunnel built under major roads.

The first 2 km section was completed in 1997, and it can hold the runoff of 50 mm of rain falling in one hour.

Plans call for the tunnel to be extended to Tokyo Bay, literally creating a second, underground Kanda River.

It serves as the venue for all of the anime version's Jet Racing and VR training sequences as well as assorted other activities throughout the series.

The Kanda River in Nakano . The Tokyo Metropolitan Government Building is in the background
The Kanda River at Ochanomizu Station . The Chūō Line runs along the river