Sエス Series by Saki Aida, Chiharu Nara, Christina Chesterfield

As the man passed by, Shiiba caught a whiff of a sweet fragrance. The man turned back to Shiiba meaningfully. Once again, their eyes met. With their eyes still locked, Shiiba pressed the close button. The doors slowly closed, finally breaking their gaze. Welcome to Shinjuku district's Kabukicho, Japan's red light district. Here, the streets are dotted with bars, pachinko parlors, and "love hotels," which cater to all sexes and sexual orientations... moreAs the man passed by, Shiiba caught a whiff of a sweet fragrance. The man turned back to Shiiba meaningfully. Once again, their eyes met. With their eyes still locked, Shiiba pressed the close button. The doors slowly closed, finally breaking their gaze. Welcome to Shinjuku district's Kabukicho, Japan's red light district. Here, the streets are dotted with bars, pachinko parlors, and "love hotels," which cater to all sexes and sexual orientations. These are the streets which Detective Masaki Shiiba must patrol. A recent rise in gun crimes forces Shiiba to go undercover and work with an "S" or spy, a member of a crime organization tasked to hand over information in exchange for special favors. Shiiba's S is a man from the influential Matsukura Group, and someone who seems to have developed a fondness for Shiiba. But when the detective gets a mysterious call warning him about his S, seeds of doubt are planted. If he can't trust his S, who can he trust? less

Detective Masaki Shiiba’s informant or “S,” Keigo Munechika, has proven himself to be an excellent source of information. But the payment of sex for every lead given is taking its toll on Shiiba. But with his new assignment as back-up to a fellow undercover detective, Shiiba learns that there are far worse things than having sex with your male S—falling helplessly in love with him, for example... moreDetective Masaki Shiiba’s informant or “S,” Keigo Munechika, has proven himself to be an excellent source of information. But the payment of sex for every lead given is taking its toll on Shiiba. But with his new assignment as back-up to a fellow undercover detective, Shiiba learns that there are far worse things than having sex with your male S—falling helplessly in love with him, for example. S volume 2 continues the drama and passion between a detective and his spy set in the highly-charged underground world of Tokyo. less

For almost a year now, Shiiba has been using Keigo Munechika as his “S,” his spy, to get information on the gun dealings of the Yakuza world. Shiiba uses his body in exchange for Munechika’s sensitive information... and only his body as far as Shiiba is concerned. Shiiba vows their relationship will not go beyond that... moreFor almost a year now, Shiiba has been using Keigo Munechika as his “S,” his spy, to get information on the gun dealings of the Yakuza world. Shiiba uses his body in exchange for Munechika’s sensitive information... and only his body as far as Shiiba is concerned. Shiiba vows their relationship will not go beyond that. But when a rowdy young man with a penchant for piercing and an enigmatic Yakuza leader cross paths with the young detective, sins of the past are unearthed once more-sins that just might shatter the fragile bond between the detective and his “S.” less

At the end of S volume 3 , detective Masaki Shiiba was last seen running away from the hospital room of his injured S, Keigo Munechika. Now, Shiiba has turned in his resignation, bought a gun of his own, and is bent on only one mission—to kill Takanari Godou. He vows to get the truth from Godou, even if he has to throw away his morals and life to do it. But can he do it? Can he shoot another person and commit cold-blooded murder for revenge?