Everyone has something precious to them. For Leon Kipling, it's his guitar. He got it from a relative back when he was living in Kenya, and it's what he takes with him on stage at his concerts. The only time he doesn't carry it with him is when he's in a fight. (He doesn't want to scratch it).

That may be another reason why he fights with Capoeira. Since it's mostly focused on kicking, the hands are rarely used, except for helping with the more acrobatic techniques, and the occational slap. Leon probably doesn't want to wreck his hands before a big show.