Inokashira Park, a brief walk away from Kichijoji Station, is mainly known for its beautiful cherry blossoms, which reflect on the lake. However, the park is perhaps even more stunning in autumn, when you will find long trails of bright red momiji and golden ginkgo trees.
Kichijoji is slightly colder than the rest of Tokyo, so the leaves at Inokashira Park change color earlier than their more centrally located cousins.
On autumn weekends it is a popular spot for a stroll, as the park comes alive with performers and artists selling their creations, not to mention some of the best-dressed dogs in Tokyo.
I highly recommend stopping by the very charming Blue Sky Coffee (located right along Inokashira Pond) for a cozy latte or mulled wine and meander slowly throughout the various areas of the park.
If you want to extend your walk, there is a trail that will take you all the way to the Ghibli Museum in Mitaka.
Inokashira Park: https://www.kensetsu.metro.tokyo.lg.jp/jimusho/seibuk/inokashira/en_index.html
Google Maps: https://maps.app.goo.gl/BQY1WAkjPf7Jy78B9
Blue Sky Coffee: https://maps.app.goo.gl/joSe9jrSnPExNdJd6