|Name in Japanese||ほたる|
|Voice Actor (Japanese)||Miyuki Sawashiro|
|Voice Actor (English)||Jessica Boone|
Hotaru (ほたる Hotaru ) is a fictional character. She is a girl who has a crush on Okita. She becomes an assistant to Ayu, but later is revealed to be a spy for the Chōshū clan. She decides to quit being a spy, and ends up being tricked by Kichisaburo, thinking he is Okita. She frees Saitō, Hijikata, and Okita from the Eight Element Battle Formation without realizing it by peeling off the seals.