The Chiba McDonald's Map overlays McDonald's restaurant locations onto a choropleth map of Chiba Prefecture, visualizing store density through a red-tinted square grid. It uses Leaflet to render the map, with D3.js queueing and parsing two GeoJSON files: one for restaurant points and one for administrative boundaries. Turf.js generates a square kilometer grid, and a custom style function colors each grid cell by counting the number of stores within it, increasing opacity and border weight as store counts rise. Clicking a restaurant marker reveals its name in a popup.