This boulevard inside Jing奴-gaien (the public outer gardens of Meiji-jing奴) is lined with gingko trees. For a couple of weeks around late November and early December, the trees 鈥 which for some reason in Tokyo are always sculpted into soft-serve like spires 鈥 turn golden yellow (which means when the leaves fall the streets are literally paved with gold.
The gingko is actually Tokyo's official tree; once you realise this you'll see the motif of the fan-shaped leaf everywhere. For Japanese, 滨肠丑艒-苍补尘颈办颈 is an instantly recognisable image of Tokyo, often used as visual shorthand for the city in TV and film.