Knuckle Girl (ナックルガール) is a 2023 Japanese action crime film directed by Chang, starring Ayaka Miyoshi,[1][2] Hideaki Itō, and Yōsuke Kubozuka in the lead roles.
Ran discovers a lead of her younger sister Yuzuki (Kotona Minami)’s disappearance that takes her to an underground fighting ring owned by the mysterious organization.
Suspecting that her sister may be involved in a crime, Ran decides to confront the organization to uncover the truth.
However, things take a turn when Nikaido (Hideaki Itō), a powerful figure in the organization offers to return Ran’s sister on one condition: she must participate in a no-rules deathmatch.
With danger at every turn, Ran must trade in her boxing gloves for brass knuckles and fight with all her might to uncover the truth and save her sister.