I wrote about CW-X CONDITIONING STORE in Omotesando before. I found an ad of their Hanzomon branch near Hanzomon Station ticket gate after run+meeting the other day.
The light was off due to saving power.
東京都千代田区麹町1-1 ワコール麹町ビル 1F
Sun. and holidays 7:00-18:00
They offer compression stockings' rental service. It's good that you can try it before you buy it.
They are located at the west side of Imperial Palace.