[Sayama City, Saitama Prefecture] "13th Unoki Firefly Evening" Nurtured by Local Residents in the Elementary School Biotope

"Unoki Nature Preservation Society" and "Unoki Fireflies Take Flight Society" held the "13th Unoki Firefly Evening" on June 13 (Sat.) and 14 (Sun.), 2026, at the biotope (schoolyard pond) of Sayama City Irumagawa Elementary School. This event, co-hosted by Irumagawa Elementary School and the Unoki District Neighborhood Association, was a popular early summer tradition for the region, attracting many families.

Background of the Event: 13 Years Since Residents' Desire to Protect Spring Water Began

Fireflies, once commonly seen throughout Sayama City, have declined with urbanization. Currently, fireflies are limited to very few areas within the city, such as the Okutomi district and Chiko-zan Park. In this context, prompted by the improvement of a nearby walking path in 2013, the "Unoki Fireflies Take Flight Society" was formed at the call of Mr. Yoshiaki Oba, then a resident welfare commissioner and now the chairman, with the aim of "protecting the rich spring water in our community and creating a place where fireflies can fly in the future." The first event was held that same year at Unoki Shimizu Park, known for its abundant spring water. Subsequently, the activity moved to the elementary school's biotope, and the community and school have worked together to protect the environment where fireflies thrive.

The Event: "They're really fireflies!" Children's Cheers Echoed Through the Night

On the day of the 13th event, the weather was clear despite the rainy season, and many local residents and families attended. As the faint glow of fireflies illuminated the darkened biotope, children exclaimed, "They're really fireflies!" and "There are so many flying!" filling the venue with smiles throughout the evening. It was a valuable opportunity for children to experience firsthand the importance of the environment by observing fireflies in the familiar schoolyard.

Comments from Organizer (Yoshiaki Oba)

This year marks the 13th "Firefly Evening" hosted by the "Unoki Fireflies Take Flight Society" and "Unoki Nature Preservation Society." With the cooperation of Irumagawa Elementary School and the Unoki District Neighborhood Association as co-hosts, we have held this event so that children and adults alike, from children to the elderly, can see and enjoy the live spectacle of fireflies glowing and flying. We aim for children to learn the importance of the natural environment, and for the community to foster connections that contribute to a safer and more secure life.

We are deeply pleased if everyone enjoyed it, and it gives our staff a great sense of purpose.

However, there were many challenges in holding this viewing event at the Irumagawa Elementary School biotope, which began with the preservation of the Irumagawa spring water.

These included the cost of repairing the wind power generation system to switch to powered generation due to damage, and the maintenance of the firefly habitat.

With advice from the community center, our staff drained the pond, cleaned it, built a homemade purification system using powered generation, and further created a firefly habitat by installing nets to prevent them from escaping the pond, planting moss for the natural environment, and releasing goldfish and medaka.

Furthermore, we set up aquariums in the school corridors so that students could observe the firefly life cycle, releasing larvae and their food, river snails, and displaying informational materials to teach them about the importance of the natural environment.

However, due to COVID-19 countermeasures in 2020, we were unable to enter the school, and the aquariums had to be removed from the school premises. With the support of the local community, we were able to continue raising fireflies in the schoolyard biotope and in aquariums at the staff's homes, leading to the current "Unoki Firefly Evening."

We are grateful for the support of many people that allows us to hold this event.

We received a letter of appreciation from Sayama City.

We would also like to report and express our gratitude to Mr. Yukihiko Nakagawa of Unoki Pharmacy (now deceased) and Mr. Akira Kojima, former neighborhood association chairman, who provided guidance from the beginning and raised fireflies at their homes.

We kindly request your continued cooperation and support for "Unoki Firefly Evening" so that many people in the community can enjoy it, and it remains a rewarding community activity.

Bamboo lights illuminated the venue, and both children and adults cheered at the sight of the fireflies.

Event Overview

Event Name: 13th Unoki Firefly Evening

Date and Time: June 13 (Sat.) and 14 (Sun.), 2026

Location: Sayama City Irumagawa Elementary School Biotope (Schoolyard Pond)

Organizers: Unoki Nature Preservation Society, Unoki Fireflies Take Flight Society

Co-hosts: Sayama City Irumagawa Elementary School, Unoki District Neighborhood Association

Number of Visitors: Approximately 400

Distributor

Sayama City Hall https://www.city.sayama.saitama.jp/