A guy taking the test before me drove the course very slowly. He also made many mistakes on the course. Afterwards, the instructor/policeman told him he needed to drive more confidently, and not make the mistakes he did during his driving test. He didn’t steer the car smoothly while turning, very jerky, and just seemed very very nervous.
If you don’t feel confident before taking the test, try taking driving lessons at the Driver’s License Center. It will build up your confidence and driving skills so when you go out on the course, you’ll be more confident.
According to one of the guys I talked to while waiting to take my test, it only costs a few thousand yen, 5000 or so, for one hour practice driving on the course with an instructor.
If anyone knows the exact cost, please let others know here.