This example presents a zoomable choropleth map of Japan’s administrative regions, rendered as SVG paths filled with distinct colors from a categorical scale. Using D3 v5 and d3-geo-projection, it applies a Mercator projection clipped to the viewport, with pan and zoom enabled via d3.zoom. Geographic boundaries come from TopoJSON data (JPN_adm1), processed with topojson.feature and drawn using d3.geoPath. The map highlights each prefecture uniformly, with white strokes separating regions.