Fighting Girl is a Japanese television drama starring Kyoko Fukada.
She is fired from her part-time job in a dress shop because she is too diligent at catching shoplifters and slaps them around a bit when she does.
Coming home on the train, she nonchalantly puts on her makeup and changes her shirt, oblivious to the other passengers' silent glares, until Ami (South Korean actress Yoon Son-ha) confronts her.
A few days later Ami is also the one who comes to the aid of Sayoko's sister, who has sprained her ankle when pushed on the platform.
Life gets more complicated when Sayoko goes to the beach to sulk and comes across a frustrated rich kid who she fends off with her considerable kickboxing skills.