The Batting Center System
You can find batting centers pretty much everywhere in Japan. Although the size and layout of each center will be different, the system is pretty much the same no matter where you go.
Above you can see the batting center at Spo-Dori in Tokyo Dome City, which is set up with eight separate batting cages.
Before you can step up to bat, of course you have to pay! This will usually be done through a machine like the one above. Some machines will give you a token ("medal") while others will give you a card.
While the amount you pay depends on which batting center you go to, the fee averages between ¥300 and ¥400 for each game. At Tokyo Dome, it's ¥400 per game, though you can save money by buying sets of three or more tokens.
After you've got your tokens, you can select which batting cage you'd like. At Tokyo Dome City, the pitch speed and style are fixed at each cage, which you'll see indicated on the signage as above.
In this case, we have 100 kilometer-per-hour (62 mph) pitches, a right-handed "pitcher" (右投手, migi toshu), and a batter's box set up for a right-handed batter (右打席, migi daseki). Note that right is 右 (migi) and left is 左 (hidari). If the batting cage you'd like is crowded, unfortunately you'll just have to wait.
You'll find bats available inside the cage; just choose the one that's easiest for you to swing. Many places will also offer batting helmets to protect your head from the onslaught of balls, so it's a good idea to put one one. Batting gloves may also be available to protect your hands from blisters and bat vibration.
Now that you've got your gear ready, it's time to start batting. To do so, simply insert a token into the machine. Some machines will also let you fine-tune the pitches. In this case, you can adjust the ball position by pushing the red button to indicate you want it thrown higher or green for lower.
Depending on the batting center, one game will give you anywhere between 20 and 30 balls. Some newer places even have pitchers on projected screens, so you can watch the pitching motion to help time your swing.