香港发生连串凶杀案, 死者均为夜之女, 杀人手法极之凶残, 凶手行凶时是驾驶电单车, 手持硬物, 将死者玩弄至根疲力尽时才下手杀人. 因案发时均为星期五晚上, 故被传媒称为(星期五杀手). 卓雄授命办理此案, 在杀手出没的地方布下天罗地网, 以五十名美艳女警为饵, 在高处安排了狙击手, 在街上满布便衣探员, 交通部更出动了三十部普通电单车, 以作追截杀手之用. 可惜行动最后失败, 健之CID女友萍更被杀手刹害, 虽然卓雄亦驾驶电单车力追, 更与杀手大打一场, 最于被杀手逃走. 自此之后, 同事们都认定卓雄是一名无人性的警察, 健更因此与卓雄结下不解仇怨…….
Choi So-young (Choi Eun-hee), a poor female law student is in trouble because her grandmother, who had been sending her tuition money, passes away. With the help of her friend Hee-suk, (Kim Suk-il) who dreams of becoming a writer, So-young fools Choi Rim (Kim Seung-ho), a lawmaker, into believing she is his daughter and moves in his house. She studies hard and becomes a lawyer. At her first trial, she defends a female inmate (Hwang Jeong-sun). Coincidentally, the story of the inmate is very much similar to hers. So-young defends her, saying how difficult it is for a woman to survive in a cold capitalism, arguing for her rights in tears. After she wins the case, she goes home and confesses her crime to Choi Rim's wife (Yu Gye-seon).
东京一隅,从事食品配送服务的执行夏希(中村映里子 饰)独自过活。这一天,名叫敷谷壮(池松壮亮 饰)的男生意外造访,她由此得知了关于父亲大悟(光石研 饰)的消息。早些年,大悟抛弃了妻子和夏希离家出走,因此在这个女孩中父亲俨然是一个令人憎恶的存在。可当父亲的形象毫无防备浮现脑海之时,她还是决定启程去探望那个男人。在东京的另一个角落,靠放高利贷为生的夏生(冲渡崇史 饰)浑浑噩噩,他无意间想起了久未谋面的妹妹(高桥爱实 饰),怎奈妹妹对于这个当初抛弃了家人的哥哥极度抵触,只是兄妹俩的那份情感血缘却割舍不断。