Double Fake: Tsugai Keiyaku

"This isn't an oath, it's a contract." An omega opening a detective bureau, Jitsuya Idou, has a pair. Kazuhiro Kitakouji, Jitsuya's alpha, is an elite detective from the Metropolitan Police Department. Together they're business partners who made a mutual agreement to become a pair. Jitsuya uses this pair to control his omega constitution. As an "S," Kitakouji uses Jitsuya for insider information. Even though it was meant to be a cut and dry relationship, an omega's body needs to have sex regularly with his pair. Involuntarily, Kitakouji and his omega's body are forced against their will. The most vexing for both of them, the sex with their pair is the best they've ever had. While continuing this distorted relationship, an illegal drug case aiming at omegas is at large!? (Source: Media Soft, translated)