Visiting the historical Sankeien Gardens and enjoy the warm-glow of the fireflies. Opening hours are extended for the firefly evenings (until 9pm with last admission at 8:30pm), but the walking area is limited for safety and to avoid bottlenecks. See here for suggestions on other places to enjoy the fireflies in and near Tokyo.
Event details are taken from official sources whenever possible. It is always prudent to check the official event website before attending to make sure that there have not been any changes. If you know of an error in the calendar, then please let us know through the contact form.