While many have cursed the early arrival of rainy season this year, the moisture-loving insects such as the firefly are likely to be in heaven.

Residents of Fussa in Tokyo, however, must be hoping that the rain stays off this Saturday evening for the annual Firefly Festival. Large numbers of visitors from the surrounding areas are expected to swarm to the city's Hotaru Park to watch the riverbanks light up. The best viewing time is said to be from around 7 p.m. In addition to the fireflies, there will also be a whole host of traditional food stalls and other festivities taking place along the town's streets throughout the day.

The appropriately named Hotaru Park ("hotaru" is the Japanese word for "firefly") is situated next to the city's meandering Tsuri River. Local hearsay has it that the lightening bugs are secretly released for the festival by a small group of locals that breed them during the year. Both the river and the park have since become notable for their abundant amount of fireflies, with local authorities having even invested in a special hotaru no yakata (firefly house) to watch the seasonal display from.

While the celebrations are just a one-day event, the fireflies will be around for a few weeks longer. A stroll along the riverside toward the mountains could make for a pleasant summer evening.

The Firefly Festival takes place at Hotaru Park in Fussa, Tokyo, on June 11 from 1 p.m. to 8 p.m. Admission is free. The park is a five-minute walk from Ushihama Station on the Ome Line and Kumagawa Station on the JR Itsukaichi Line. The event is subject to dry weather.