A no-nonsense detective with a reputation for pushing limits investigates a rash of brutal murders connected by a series of cryptic short stories.

Natsumi Yukihira (Ryoko Shinohara) receives secret documents of an organization that controls the country from the shadows. Because of this, Natsumi's ex-husband, Kazuo Sato (Teruyuki Kagawa) pays a terrible price. Natsumi goes back to the Investigation #1 of Tokyo Metropolitan Police Department to take on the organization, but Natsumi becomes involved in a new case. She gets closer to the final enemy.

曾经的警界精英真岛拓朗（玉木宏 饰）一年前在追查嫌疑人时导致下属遇害，从此遭到同侪排挤，其本人也自甘沉沦。当听说最信赖的上司三轮周平（モロ師岡 饰）失踪时，真岛重整旗鼓，展开调查。在此过程中，他偶然邂逅美丽女子野上芽衣子（菅野美穗 饰）。芽衣子是东京某宠物沙龙的职员，她温柔可亲，善良随和，但其阳光般的笑容背后却有着悲伤的过去。十五年前，芽衣子被控杀害了姐夫和外甥，饱受牢狱之苦的她决定向当年那些罗织罪名陷其入狱的人展开复仇。与此同时，真岛在追查三轮管理官下落的过程中，发现近一段时期发生的几起死亡事件背后有着千丝万缕的联系。 疑点几乎渐渐聚焦在芽衣子的身上，而真岛和她的命运也紧紧缠绕在一起……

After detective Natsumi Yukihira brings an end to the police hospital terrorist case, Natsumi is transferred to the Nishimonbetsu Police Station in Hokkaido. Meanwhile, a series of grotesque murders occurs in downtown Tokyo involving nails placed in the body of the victims. The fingerprint of Natsumi's ex-husband, freelancer journalist Kazuo Sato, is found on the the body of a victim and Kazuo is placed on the most wanted list. Soon after, Kazuo finds Natsumi and hands her a USB memory stick. The device contains information on a secret organization within the police department. Kazuo tells Natsumi that the series of murders are warnings and suspects become the next victims. Natsumi is then arrested as a suspect. Tokyo prosecutor Katsuaki Murakami appears at the Nishimonbetsu Police Station to investigate.

After the death of this mother, Masao Oneta (Teppei Koike) decides to leave the comfort of his room after years of self isolation and get a job. He lands a position at a small IT firm but doesn't yet realise this company is one of many 'black companies', known for overworking their employees.