A wealthy woman named Hisako Osada is found murdered in a briefcase that was delivered to her home. Whilst the police suspect Hisako's lover to be the culprit, her daughter, An, believes someone else is behind the murder and calls on Shinjūrō to investigate. Their investigation leads them to look into an idol group Hisako managed named Yonagahime 3+1, one of its members of which, Eri, was allegedly killed in a terrorist attack. Inga uses her powers on one of Yonagahime's members, who reveals that Eri never existed and was just used by Hisako to skyrocket the band's popularity during a war.
Un-Go is set in a war-torn Tokyo, in a near-future Japan. In response to Japan sending their military abroad as peacekeeping forces, terrorists launched multiple attacks on Japan, killing many people and destroying much of its cityscapes. Some time after the war receded to a period of uneasy peace, the Japanese Parliament passed the "Information Privacy and Protection Act", which gives the Japanese government control over the Internet. Detective Shinjuurou Yuuki and his strange partner Inga make a living in solving crimes and exposing human souls, all influenced in some way by the dystopian backdrop.
