Places to Play: Sophia University (Yotsuya)
 
Sophia has 4 clay courts in its athletic grounds next to Yotsuya station.  These grounds are a filled-in part of the outer moat of the Imperial Palace, separated from Sophia by an earthen embankment that has cherry blossoms in the spring.  (How the moat became filled in after WW2 is another story).  You need a university connection to use these courts.
 
As a graduate of Sophia, I have many peripheral memories associated with these courts.   Tennis-wise, my memories are mostly that I was jealous of how tightly the college tennis team controlled these courts!  I wasn't good enough at the time to be on the team, and played with a group of classmates next to a prison in Nakano (but that's another story too...).  I think I was on these courts maybe twice during my college years.

I know some of the professors there from my alumni association involvement.  I played Fr. Garralda on these courts a few years ago.  He beat me soundly, unfortunately.  I suspect he had Help from Above since he is a priest.