This example displays the population of Japanese prefectures as bar charts, with options to view total, male, female, or combined gender data. For the combined view, it draws paired bars using SVG rectangles within a React component, animated via the `animate` element. Users can hover over a color legend to highlight one gender while dimming the other. Data is loaded as CSV using d3.csv, with scales built via d3.scaleBand and d3.scaleLinear, and axes rendered as custom React SVG groups.