The kanji 蛍 (firefly) represents the insect known for its bioluminescence, the firefly. It signifies light, specifically the soft, glowing light emitted by this creature. It often evokes imagery of summer nights, natural beauty, and the delicate nature of the firefly itself. It can also imply the idea of a fleeting or ephemeral light.

・On-yomi (音読み): ケイ (kei) ・Kun-yomi (訓読み): ほたる (hotaru)

⚫︎蛍火 (hotarubi) Translation: Firefly light. ⚫︎蛍雪の功 (keisetsu no kou) Translation: The fruit of diligent study; literally, "the merit of fireflies and snow." (This refers to a story about a scholar who studied by the light of fireflies and the reflection of snow.) ⚫︎蛍狩り (hotaru-gari) Translation: Firefly hunting (a traditional summer pastime in Japan).

The kanji 蛍 is a phono-semantic compound (形声文字, keisei moji). The left side is a radical (偏, hen) that represents insects (虫, mushi). The right side, 兄 (kyou), is a phonetic component, representing the sound of the kanji. Initially, the original form depicted the insect itself, with emphasis on the shining light. Over time, it developed to the present form with the "insect" radical indicating its nature.