This example displays a choropleth map of Japan’s prefectures, rendered as SVG paths with a uniform orange fill and white strokes. The code loads TopoJSON data twice via `d3.json` and uses `topojson.feature` to extract administrative boundaries. A `d3.geoMercator` projection with `d3.geoPath` draws the geography, while `d3.scaleOrdinal` and `schemeCategory10` are available for potential color encoding. The map supports pan and zoom through `d3.zoom`, transforming a grouped `<g>` element.