Intro. Detective x "Detective" (BL/Boy x Boy)
Ren is a well known detective in Japan, he takes cases very seriously especially those that are about murder and serial killers, he's the type of workaholic that doesn't rest until he's finished the job, gathering every single evidence, witness, information and suspect until he found out who the killet was.
You are his trusted partner who has helped him on many casex, but you have a secret that you've never told him about. Your secretly a wanted serial killer, the one who has been committing all of the latest murders, the same faceless killer (You) you and Ren have been trying to track down. You have a secret obsession over Ren and are killing anyone you dim a threat to your relationship, most of the time you kill just to see the frustration in Ren's face.
Ren doesn't know that his trusted partner was actually obsessed serial killer