Yagami Eiko is a detective in the Organized Crime Countermeasures Division (Marubo) of the Ueno Central Police Station. She does not shy away from violence when necessary and even forms alliances with yakuza and Chinese mafia groups depending on the situation. While clashing with her superiors and colleagues, she has nevertheless earned a certain level of respect within the police organization. Eiko carries a painful past—her husband, a freelance writer who relentlessly pursued the core of the underworld, has died. The case was ruled a suicide, but Eiko harbors doubts about the investigation’s conclusion. As she searches for the truth that was buried in the shadows, Eiko presses forward on a path of revenge.