These 4 lighted courts in Arisugawa Koen (park) may be the centerpiece for non-club tennis play in central Tokyo. The courts are very convenient for the large number of foreigners in the area. They are reasonably well kept, and with the artificial lawn are useable within minutes after a rain (in contrast, the Tokyo Lawn Tennis Club - just a fence or two away - is out of action for a day or so after a good rain). The courts have lights, and evening play from April to October is popular given the nearness (no evening play in the winter). The money cost of the courts is very cheap (well, your taxes pay for them, but ...) although you do have to put in time to get use.
If you can play weekday daytime you can get up to 3 two-hour time slots a month. Have a group of 5 friends each doing the same and your group can play 15 times a month !
Weekend / holiday times are much tougher to get.
See the info page on the Minato Ward lottery system on how to get use.
The courts are at the broad end of Arisugawa Koen, next to a baseball field. From Hiroo subway station, go to the National Azabu supermarket. Arisugawa Koen is triangular in shape, and its pointy end is at this supermarket. Go up the street in front of the supermarket with the park on your left. The courts will be at the first traffic signal.
Remember to bring the receipt you got at the Tamachi sign-up, and show it to the admin office before going onto the court. About 5 minutes from the end of your time slot, an announcement (in Japanese) is made about sweeping the courts to even out the sand. The admin staff will get angry with you if you don't sweep the courts !