The Japanese associate fireflies with the souls of soldiers fallen in battles, so these lighting bugs occupy a special place in Japan's culture. They have been venerated in poetry and traditional fine arts, where "hotaru" also serves as a metaphor for a romantic passion. When summer arrives in Tokyo, people fill parks and gardens in the Japanese capital for fireflies just like for sakura blossoms in the spring.
Chinzanso Firefly Fantasy (May 22–July 12, 2020)
Chinzanso Garden is one of the best places to watch fireflies in the middle of the megapolis. This large green park by the Tokyo's Hotel Chinzanso has been featuring firefly watching since the 1950s. Benkei Bridge area usually has the most fireflies and best views. The hotel also offers romantic dinner settings in the garden during the firefly watching season in the park that usually lasts from late May through early July. The best time to see the magical nature's show is at 9 pm. The entrance to the garden is free.
Hotaru No Yube at Botanical Garden Fureai (mid-June)
It's hard to imagine that one can encounter fragile fireflies in the middle of the busy Shibuya district. However, Japan's tiniest indoor botanical garden is indeed showcasing lightning bugs that live over its ponds on select 3 or 4 nights in mid-June. This free annual event attracts about 10,000 people every year, so it might get rather crowded. If you prefer to see fireflies in a larger open-air park amidst a countryside setting, opt instead for Hotaru no Yube at Yuyake Koyake Fureai no Sato park in Hachioji, which is usually held at the same time.
Setagaya Firefly Festival (mid-July)
Many towns host Hotaru matsuri or firefly watching festivals, complete with live music, drums, craft, and art markets, as well as delicious summer treats. Setagaya that is famous for its "good luck cat" souvenirs, holds the firefly festival during two days every July. The festivities take place at Setagaya Daikanyashiki from 5 to 9 pm. The major highlight of the festival that attracts over 20,000 people is the release of 3,000 fireflies under the dome temporarily put over the nearby car park. The dome is open to visitors after 7 pm.
Kugayama Firefly Festival (first weekend of June)
Kugayama neighborhood holds its annual firefly festival on the first weekend of June. It's a smaller and more community-oriented event, comparing to Setagaya. The stalls are set up along Kuguyama's main commercial area with shops and restaurants. In addition to music, shopping, and food, the festivities also feature the release of fireflies. The best spots to watch the fireflies are by the banks of the Kanda river and Tamagawa Josui River that flow through the city.