Hotaru is a very mysterious character. It is unknown how old he is, what he does for a living, or whether 'Hotaru' is his real name. The only certain facts about him are the physical ones. He is about 5½ foot tall, has a muscular build, is very skilled gymnastically, and has incredible magical skills. Some have also commented on his singing voice, and how he sounds naturally attractive when he speaks, though he doesn't actually talk very much.
Hotaru is generally very kind and thoughful. However, not much can be told about him, since he barely ever talks.