Interrogation and Conspirator is the fourth chapter of the manga Ajin Demi-Human, written by Tsuina Miura and illustrated by Gamon Sakurai.
The story then cuts however, showing that Kei and Kaito are residing in the bathroom of an abandoned building talking about where they should go from there. Kaito tells Kei that he has grandparents living in a small community inside Kyushu and that they won't mind any Ajin there. Kei tells him that he thinks it is the best possible solution and that he couldn't have thought of it alone. Kaito says that they should hide there while it's light outside and that he'll go buy some clothes.
We then see Izumi questioning Eriko about Kei and the unknown accomplice (Kaito). Eriko says that it's disgusting to think that he was part of her family, and Izumi responds by saying while she can't understand what having an Ajin in her family is like, she doesn't want to see more people like them or Eriko, and so wants to know more about Ajin. Izumi asks if there is anything Eriko can tell her about Kei that will help with her investigation. Eriko tells her about the time when her pet dog died where Kei said something "weird".
The story cuts to a flashback where we see Kei trying to protect Eriko from his Black Ghost, unaware that she cannot see it. Izumi is shocked to hear this and asks her in a loud voice if Kei saw the Black Ghost, before realizing she has said too much already. Reminiscing about the time she spent with her brother and Kaito when she was younger, Eriko realises that Kaito may be the unknown accomplice assisting Kei, but before she can tell anyone, Izumi is impaled by Tanaka's Black Ghost.
The Black Ghost continues to attack and kill the other two police officers in the room , causing Eriko to pass out from shock. From there we get a very brief glimpse of Kei, still inside the bathroom questioning whether or not there are humans who don't mind Ajin.
Quickly though we cut back to Tanaka's ghost inside the hospital room, who is gazing at Eriko's unconscious body. It is then revealed however that Izumi is in fact an Ajin after she comes back to life completely regenerating from her wounds, and she tells him to move away from Eriko. The story cuts one last time to Kei who says "I'm an Ajin", revealing that he has been staring at his Black Ghost for some time.