Stray Cat Rock: Delinquent Girl Boss (1970) aka Nora-neko rokku: Onna banchô aka Female Juvenile Delinquent Leader: Stray Cat Rock
"Yasuharu Hasebe developed and directed this first installment in a five-film series dealing with the adventures of an all-girl motorcycle gang. Pop singer Akiko Wada heads the distaff bikers in this episode, with the gang involved in rigging boxing matches until the yakuza intervenes by killing Wada. Her assistant (Meiko Kaji) takes over the gang, which then gets revenge on the mobsters. Good-looking and fast-paced, this film and its sequels are typical of Nikkatsu Studios' slick output before they dedicated themselves to erotica as the decade progressed. Stray Cat Rock : Wild Jumbo (1970) and two more sequels followed later in the year."
Film available over here