Yes, it is mandatory to wear a motorcycle helmet in Japan. The Japanese Road Traffic Act (also known as the Road Traffic Law) requires all motorcycle riders, including passengers, to wear approved helmets while riding on public roads. This law aims to ensure the safety of riders and reduce the risk of head injuries in the event of an accident.
The helmet must meet certain safety standards and display the appropriate certification marks. In Japan, the most widely recognized standard is the Japanese Industrial Standard (JIS), specifically JIS T 8133:2000. Helmets meeting this standard usually have a JIS certification sticker or label attached to them.
It's important to note that laws and regulations can change over time, so it's always advisable to check for the most up-to-date information from reliable sources or consult local authorities if you have any specific questions regarding motorcycle helmet requirements in Japan.