I think everything shown so far exists in one way or another.For those who are curious, the Sewerage Museum in Kodaira does exist: https://maps.app.goo.gl/n8zLrYDZE9Ub7iaQ8
should add a tourism tag on this manga, since yes, it does feature real life locations on a visiting tourism aspect.For those who are curious, the Sewerage Museum in Kodaira does exist: https://maps.app.goo.gl/n8zLrYDZE9Ub7iaQ8