Japanese names are usually chosen with great care - the sound, the meaning of the words and the appropriate ideogram should be considered. I got curious about the GB guys names and made a little research. This is what I have found so far:

Ban - as almost everyone knows, it means "demon". Curiously his surname, Midou, means something like "beautiful temple".

Ginji - "gin" means "silver" and "ji" means "the second, the following". "Ama" means "heaven" or "god". "No" means "natural" or "wild".

Akabane - "Kurodo" means "black person". Akabane means "red wing".

Kazuki - "Kazuki" means "moon flower". "Fuu" means "wind"; "cho" means "bird" and "in" means "noble people or the place where they live".