Chapter one

The first chapter of the series introduces the tritagonists, Risa Aioi, Sakon Futatsuki, and Ukon Futatsuki and their work with the Tokyo Metro Police, First Criminal Investigation Division.

Plot
The chapter starts off with a news broadcast announcing the entertainer Haruka Shinomiya has been found dead in her apartment. It cuts to popular actor Atsushi Tagame walking off a staging area for a tv show, when he encounters Risa Aioi. Aioi asks for a handshake, but declines and walks away when he says yes. Tagame is warned to stay vigilant around fans, as Shinomiya was rumoured to have a stalker before she died. We then see Aioi fondly placing a photo of Tagame on a wall of other photos, supposedly taken without consent.

Ukon Futatsuki and Sakon Futatsuki introduce themselves as detectives to Tagame, and begin asking him questions. They explain that Shinomiya had been killed in her apartment on her day off from a stab in the back of her head, and that they believe the culprit broke in through a window. They ask Tagame if he had any issues with Shinomiya, and he reassures them that he didn't, and explains that Shinomiya had a stalker that rifled through her garbage to find her shampoo brand, among other offences. Tagame recounts his experience with Aioi, and Sakon runs off to find Aioi. Ukon reassures Tagame that they will find the culprit soon and leaves the restaurant. Aioi whispers in Tagame's ear that she's using the same shampoo as him, before ducking under a table out of sight.

Tagame returns to his apartment, and an investigator asks to be let in to explain some new information to him. She explains that they have discovered the murder weapon, a folding pocket knife, and half a receipt that had been left at the scene. She shows him security footage of someone purchasing the knife, and asks if they look familiar. He says that he can't recognise the person. She tells him he's a skilled actor, and asks for a coffee refill despite claiming to dislike it. Sakon calls him to follow up, and he tells Sakon that he's currently with an investigator. Sakon is confused, and says there shouldn't be an investigator there, and the investigator removes a disguise to reveal that she is Aioi. She smells his laundry and says that she could get used to the smell, and he runs to the rooftop for fear of getting killed. When Aioi catches up to him, she brightens and asks him if he's Shinomiya's murderer. She pulls out her badge to reveal she is a cop.

Ukon reassures Sakon that Aioi will catch the criminal, despite having unconventional methods. Tagame is confused by the revelation that Aioi is really a cop, and Aioi unhelpfully explains that she chose her disguise because Tagame claimed to like dark hair and glasses. She begins to rant about how much she loves him, and how he ID'ed him from the scent of shampoo at the crime scene. Ukon explains to Sakon that she finds criminals by falling in love with them, and that it's a "Textbook case of fighting poison with poison". Aioi starts to chase Tagame until he fears for his life. Whenever he loses her, she searches online for sightings of an actor running through the streets to find him. She calls him and buys him a drink from a nearby vending machine, and he gets more and more fearful.

When he finally stops, Aioi explains how she discovered him. The receipt at the crime scene had been fabricated. She decided to buy her own knife from the same store, and noticed the receipt had different info. She realised this meant he had waited for someone to buy the same knife, and then forged a receipt for a pocketBOOK to say pocketBLADE, and thus framed a random civilian. She saw someone with his finger shape (she could only see his back and his arms from the camera angle ) buy the pocket book on the cameras, and therefore proved him to be the culprit. She realises that Shinomiya must have invited him over, which is how he managed to stab her in the back of the head without her noticing, and then he broke a window to make it seem like someone had broken in. He objects, claiming it was mere conjecture, but then she reveals that she read his emails off his phone and one of them was the purchase confirmation from the knife. He tells her that method of gathering evidence is a crime, but she says it's just love.

Sakon and Ukon begin driving over to Aioi, and Ukon explains why she falls in love with criminals. Aioi had been abducted in the "Myochin City Girl Abduction." Details were hazy, but she had fallen in love with her kidnapper. Aioi had since fallen in love with every criminal she could find, and was unlikely to arrest any of them. The only reason the authorities allowed her to continue these methods was because no criminal would ever want to run away with her.

Tagame, so put off by Aioi, immediately confesses to his crime to escape her. The case ends, but Sakon is upset. He is confused how Aioi is allowed to get away with "fighting poison with poison". Ukon reassures him that all that matters is that they had found the perp and Sakon had "solved" his first case. Encouraged by Ukon's words, Sakon goes to talk to Aioi. He notices her apartment is covered in pictures of perps she found. He notes that she seems normal enough to talk to, he thanks her for her assistance. She quickly explains that she didn't help him solve the case, more that no matter whether she wants it to or not, once a perp is found the case must end. He asks her why she lets these criminals into her heart, and she explains that she'd rather have them in their heart until they have to pay recompance than never have them there at all. Sakon tells her that he can't approve of her methods, and will be keeping a close eye on her.