Saturday March 30th (repeated on Sunday March 31st)
Cherry Blossom Walk along the Imperial Palace moat – from Chidorigafuchi to Hibiya Park (1 to 3 miles)
Meet at 10:00am, Kudanshita Metro Station (Hanzomon, Tozai and Toei Shinjuku Lines) Exit #2. Please see below for how to get to Kudanshita (九段下) Metro Station.
This walk will follow the pedestrian path along Chidorigafuchi Moat of the Imperial Palace, one of the best cherry blossom viewing spots in central Tokyo. According to the current forecast the estimated best viewing period in Tokyo will be between March 31-April 7 this year.
Image from Wikipedia
I did a recce for the walk two weeks ago (the place didn't look like the Wikepedia photo above but we still have 6 weeks!) and bearing in mind a number of people will be doing the palace tour on Thursday or Friday I have modified the route slightly from the original plan.
We will meet at Kudanshita subway station Exit #2 on the Hanzomon Line, Tozai Line or Toei Shinjuku Line at 10am to try and beat the crowd.

Kudanshita Metro Station
Panoramic view of Kudanshita Metro Station Exit #2 (street level)
From Kudanshita station it's a short walk to the start of the footpath along the moat. We will walk along the footpath passing the entrance to Chidorigafuchi National Cemetery and the British Embassy to Hanzomon Gate. Some more images of cherry blossoms in the area may be found
here. Those who do not want a longer walk can leave the group and catch the subway from Hanzomon Station, which is a little over one mile from Kudanshita.
We will then walk passed the National Theatre (Kokuritsu Gekijo), Supreme Court, National Diet Library, and the National Diet (Japan’s legislature) Building to Sakuradamon Gate of the Palace (formerly Edo Castle), the site of the assassination of the Japanese Chief Minister in March 1860. The gate is currently being restored but according to the notice posted the restoration work should be completed in March 2013. Let's see if they are right.
Image from Wikipedia
We will walk through Sakuradamon Gate into the large plaza in front of the Imperial Palace to look at two of the most photographed bridges of the palace that form an entrance to the inner palace grounds.
Image from Wikipedia
It will be about 3 miles from Kudanshita to Nijyubashi according to Google Maps.
http://goo.gl/maps/dwp6l
There are subway stations on the route for anyone who wants to make the tour shorter. We will also be close to Tokyo and Yurakucho stations. Those interested might go for lunch in Hibiya Park or somewhere nearby. This map from Japan-Guide should give you an idea of the area of Tokyo covered by the walk.
How to get to Kudanshita Metro Station (九段下駅)
From Shinjuku : Toei Shinjuku Line (S01) to Kudanshita (S05). Runs every 5-6 minutes and takes 8 minutes.
From Roppongi : Toei Oedo Line (E23) to Aoyama-itchome (E24), change to Tokyo Metro Hanzomon Line (Z03) to Kudanshita (Z06). Takes about 15 minutes.
From Shinbashi : Tokyo Metro Ginza Line (G08) to Nihonbashi (G11), change to Tokyo Metro Tozai Line (T10) to Kudanshita (T07). Takes about 12 minutes.
From Shinagawa : JR to Shinbashi then follow the route above. Takes about 21 minutes.
Please let me know if anyone needs to know how to get there from areas not mentioned.
Tokyo Subway Map