This example displays Japanese population data by prefecture from a CSV file, initially showing a loading message while fetching the data. The visualization uses React with hooks like `useState` and `useEffect` to manage asynchronous data loading via the `csv` function from d3.v5. The code processes each row to extract the prefecture name and concatenates them into a message string, which is then rendered as large text in a `<pre>` element. The layout of the page is a map of Japan, but the code focuses on printing the prefecture names as a text-based output.