This example displays a choropleth-style map of Japan’s administrative regions, rendered as SVG paths with an orange fill and white strokes. Users can pan and zoom the map via `d3.zoom`, which applies a transform to the grouped map elements. The code uses `d3.geoMercator` for projection, `d3.geoPath` to generate paths, and TopoJSON’s `feature` to parse the geographic data from a remote JSON file. A categorical color scale (`d3.scaleOrdinal`) is also defined, though the visible map uses a fixed CSS fill.