Etymology: Derived from the Japanese words 'naka' (中) meaning 'middle' or 'center', and 'shima' or 'shima' (島) meaning 'island', though here altered phonetically to 'nishi', which can also relate to 'west' in other contexts—but in this case, it refers historically to a place name or topographical feature. The name likely originated as a locational surname for someone living in or near the middle of an island or central district.