prevailing form of youth delinquency within Japan. Numbers slowly began to decline following the 1980s peak. It is reported that, by the 1990s there were around 28,000 sprinkled throughout the country. In 2004, the Japanese government passed a revised road traffic law which gave the police more power to arrest bikers riding recklessly in groups. With increased arrests and prosecutions, participation rapidly went into decline. As of 2010, police reported that the new trend among was to ride together in much smaller groups and to ride scooters instead of heavily modified motorcycles. Aichi prefecture was reported to have the highest number of riders, followed by Tokyo, Osaka, Ibaraki and Fukuoka. By 2015, there were only a reported 6,771 active throughout Japan. In 2013, the National Police Agency re-classified biker gangs as "pseudo-yakuza" organizations. Traits are usually between the ages of 16 and 20 years old. They are known for their style that heavily mimics greaser culture within the United States. This includes a pompadour style haircut, uniforms, which were often modified and embroidered jumpsuits, inspired by those worn by manual laborers during the WWII era, baggy pants and military boots. were often embroidered with various slogans and large, intricate designs. They were seen as a status symbol to many, symbolizing both their pride in themselves and their strength. They were often worn open in the front, with bandage wrappings around their waist. They would also often be accompanied by rounded sunglasses and sashes. The word is also applied to motorcycle subculture with an interest in motorcycle customizing, often illegal, and making noise by removing the mufflers on their vehicles so that more noise is produced. These groups sometimes ride without motorcycle helmets (which in Japan is illegal), also engage in dangerous or reckless driving, such as weaving in traffic, and running red lights. Another activity is speeding in city streets, not usually for street racing but more for thrills. With many bikes involved, the leading one is driven by the leader, who is responsible for the event and is not allowed to be overtaken. Japanese police call them (police code or ) and occasionally dispatch police vehicles to trail the groups of bikes for the reason of preventing possible incidents, which may include: riding very slowly through suburbs at speeds of , creating a loud disturbance while waving imperial Japanese flags, and starting fights that may include weapons (such as