Getting a license
If you already have a motorbike license from another country, you can be issued with an equivalent Japanese one. If you have a Japanese car license, you can ride a scooter or a motorbike up to 50cc. If you have an international bike license, you can ride a bike of any size.
If you've never ridden before, the best way to learn and to get your chugata license (up to 400cc) is to enroll in a driving school. If you have a Japanese car license, this greatly shortens the time it takes to complete the course, as only 18 hours of riding classes are required; there is no written test. Plus, Japanese proficiency is not a must to enroll. The course costs about 80,000 yen and instruction is generally excellent.
To get an ogata license (over 400cc), if you already have the chugata you can take a riding test at a driving-license center. Alternatively, you can enroll in an ogata license class, which consists of 12 hours of riding class and costs roughly 60,000 yen. If you only have a Japanese car license and want to get a big bike license, the cost of the course rises to 136,000 yen and involves 30 hours of riding lessons.