On the western side of Kiryū, there is “Gunma Insect World” that spreads over the village mountain. On the other side of the gate to the observatory’s giant hothouse, Gunma suddenly becomes a sub-tropical zone. The sweat-inducing heat and humidity there take one by surprise. Walking down the jungle’s narrow path, one is surrounded by even more surprises. On the treetops and in the streams, countless butterflies dance at ease. It is an ecosystem that has reproduced the environment of Iriomotejima, an island in Okinawa, and circulates beautifully. Everywhere in the garden, children’s eyes sparkle. The thicket where the beetles gather, the marshes where the fireflies dance, you can also experience sericulture and the making of raw silk here.


This insect garden, which is the only one of its kind in the world, can be said to be the cumulative result of Mr. Yajima’s insect research and zoo management. In 1957, he succeeded in opening an insectarium of living insects, something unprecedented in Japan. Later, he opened an insect garden in Tama Zoological Park. While the firefly breeding farm was being built in that garden, the Emperor and Empress of Japan visited, and Mr. Yajima answered their questions. Half a year later, a request came from the Imperial Household Agency for some fireflies to be housed at the Imperial Palace. At the Emperor’s request, the palace restored the nature of Musashino, with nothing added that was man-made. In 1973, with the release of larva and black snails, the project that did not permit failure began. For the next forty years, observation records were set every early summer. The fireflies settled into this perfect and safe environment and continue to multiply.


For many years on NHK radio, Mr. Yajima answered the questions of elementary school children on summer vacation. Leading children to an encounter with insects and to enlighten them as to the importance of life has been his lifelong mission.



Minoru Yajima

Born in Tokyo, 1930. Graduated from the Department of Biology, Tokyo Gakugei University. In 1957, he opened the Toshimaen Insectarium. From 1960, he worked at Tama Zoological Park. He held the positions of Aquarium Director of Ueno Zoological Gardens, Tama Zoological Park Director, and Director of the Tokyo Zoological Park Society. In 1999, he was appointed Director of Gunma Insect World, which opened four years later, and was awarded the Zoology Education Award by the Zoological Society of Japan.

Cooperation: Gunma Insect World

Spirit and Spine

created by

project direction
Gaku Okubo (ISUKE INC.)
Yoshitomo Tanaka (Vivot)
site design
title calligraphy
Kenryo Hara (Kikkokai)