About 100,000 solar-powered light bulbs were released into a river in central Tokyo for spectators to enjoy along with the lit-up Tokyo Sky Tree on Saturday (May 25).
Local districts held the Tokyo Hotaru or Firefly Festival around the time Tokyo Sky Tree opened last year to attract people to the Sumida River.
Members of the organizing group and about 15,000 pre-registered people released approximately 100,000 light bulbs into the river in turns.
The light bulbs are ball-shaped and 8 centimeters across. When placed in water, the LED inside them glows blue, using electricity generated by solar panels during the day.
Tokyo Sky Tree was also lit up in blue and white to match the light bulbs during the festival.
Many visitors enjoyed the joint display of lighting.
All the bulbs were collected and will be reused in other events.