托科的成长过程中没有受到母亲瑞穗的爱，瑞穗继续崇拜她死去的儿子。她一个人住在一间公寓里，停电了，垃圾堆积如山。一天深夜，托科进入一座阴暗的大楼，以躲避一个威胁性的跟踪者——富田。在那里她发现了一把手枪。她把它带回家，确认里面装了四颗子弹。有一天，住在隔壁的一家人已经忍受着贫困和暴力，最终谋杀了一名男子。托科帮助他们掩埋了那人的尸体，用手枪射击。托科被枪本身迷住了。由于侦探在寻找手枪和一名知道手枪秘密的可疑男子Kazunari，她进一步卷入了事件的真实情况。Toko试图把自己扔进漩涡，但她的“过去”被吹走了

Toko grew up unloved by her mother Mizuho who continues to adore her deceased son. She lives alone in an apartment the electricity has been cut off and the trash is piling up. One late night, Toko enters a gloomy building in order to escape from a threatening stalker, Tomita. There she finds a handgun. She brings it back home and confirms it is loaded with four bullets. One day, the family living next door who have already been enduring poverty and violence end up murdering a man. Toko helps them bury the man's body, shooting it with the handgun. Toko becomes captivated by the gun itself. She is further entangled in the true circumstances of the incident due to the detective searching for the handgun and a suspicious man Kazunari who knows a secret about the handgun. Toko tries to throw herself into the whirlpool but then the lid is blown off her "past."