also: げんじぼたる
noun
Genji firefly; Luciola cruciata
A species of firefly native to Japan, known for its relatively large size and bright light. Often contrasted with the smaller Heike firefly (ヘイケボタル).
夏になると、川の近くでゲンジボタルが飛び交う。
In summer, Genji fireflies fly around near the river.
Genji fireflies are larger and brighter than Heike fireflies.