The Yatsushiro Fireworks Festival will be held Saturday, October 15 from 18:00 to 20:15. This is the largest fireworks show in Kyushu and each year pyrotechnicians from across Japan compete to produce the most spectacular fireworks displays.
The fireworks will be shot off over the Kuma River in Yatsushiro City (near the Kuma River Green Area Park, 八代球磨川河川緑地). The festival may be accessed by train (get off at Yatsushiro Station) or by car (free parking will be available in some areas). This event is extremely popular, so expect roads and trains to be very crowded.
Should there be severe weather, the festival will be postponed to Saturday, November 5.
More information is available here (Japanese).