For the last class of the year in my ５年生 classes, and one of my ６年生 classes, we played the classic schoolyard game: Four Square. This wasn't really so much teaching English, as it was teaching "culture". Earlier in the year, one of the student's asked me what kinds of games students in the U.S. played during recess. I remember playing this game quite a bit when I was in school, so I figured I'd teach it to them.
It was still winter outside, so we played this in the gym. 2 of my schools had enough Line Tape to make the courts, but for the other school, I had to buy my own. Each court is 5x5 meters, so for 2 courts, I needed 60 meters worth of tape. Daiso had me covered, though, so it only cost $4 for another tape.
Explaining the rules wasn't too difficult, and after a few matches, the students can basically referee themselves without any assistance.
Overall, the really competitive kids got SUPER into this game. They were cheering, and yelling, and screaming at each other. It was hilarious. :)
Though, each game was not without some incident of a student sitting on the side line, not paying attention, then getting whacked in the face with the ball. Obviously, the softer than ball you can use, the better.
For my two classes of 40 kids, I think 2 courts was not enough. A 3rd would've kept the kids much more interested when they were on the side lines. Even my class of 32 kids could've used a 3rd court. My class of 24 students though was perfect. I think they loved the game the most, and had the most chances to play.
Also, it took 10-15 minutes to create the courts in the gym. For most classes, the teacher gave the students a blueprint and made them put it together. For one school though, I had to create the thing myself before class.