var mymap = L.map("mymap").setView([38.9018569,139.8222027], 14);
     
    document.addEventListener("DOMContentLoaded", () => {
    	var osmTile =
    		L.tileLayer('http://{s}.tile.osm.org/{z}/{x}/{y}.png', {
     			attribution:
      			 '&copy; <a href="http://osm.org/copyright">OpenStreetMap</a> contributors'
    	});
    	
    	var gsiTile =
    		L.tileLayer('//cyberjapandata.gsi.go.jp/xyz/std/{z}/{x}/{y}.png', {
    			 attribution:
     			  '<a href="http://maps.gsi.go.jp/development/ichiran.html">国土地理院</a>'
    	});
     
    var baseLayers = {'OpenStreetMap': osmTile, '国土地理院': gsiTile};
     
    osmTile.addTo(mymap);
     
    L.control.layers(baseLayers).addTo(mymap);
    }, false);
     
     
    L.control.scale().addTo(mymap);