Bōsōzoku (暴走族, literally "running-out-of-control (as of a vehicle) tribe") is a Japanese youth subculture associated with customized motorcycles. The first appearance of these types of biker gangs was in the 1950s. Popularity climbed throughout the 1980s and 1990s, peaking at an estimated 42,510 members in 1982.
They wear boilersuits similar to those of manual laborers or leather military jackets with baggy pants, and tall boots. This uniform became known as the tokkō-fuku (特攻服, "special attack clothing") and is often adorned with kanji slogans. Typical accessories to this uniform are hachimaki, surgical masks, and patches displaying the Japanese Imperial Flag.