| Hotarubi | |
| Cover: | Hotarubi(rythem).jpg |
| Type: | single |
| Artist: | Rythem |
| B-Side: | Natsu Mero |
| Released: | July 18, 2007 |
| Genre: | Pop |
| Label: | Sony Music Japan |
| Prev Title: | 'Sakura Uta' |
| Prev Year: | 2007 |
| Next Title: | 'WINNER' |
| Next Year: | 2007 |
("Firefly-fire") is Rythem's twelfth single which was released on February 28, 2007, under Sony Music Entertainment Japan label. The title track was used as the ending theme for TV Tokyo's show FIGHTENSION☆SCHOOL. This single reached the #36 spot in the Oricon weekly charts.
The item's stock number is AICL-1847.
Composition/Lyrics: Yui Nītsu
Arrangement: Satoshi Takebe
Composition/Lyrics: Yukari Katō
Arrangement: Masuda TOSH