The E-mail Mystery

「一週間後、お前は死ぬ。メーラーデーモン」

『メーラーデーモンの戦慄』

"You will die after one week. Mailer Daemon"

"The Terror of the Mailer Daemon"

 
Design-wise, I still like those old clamshell flip-phones, and I'd actually prefer them over smartphones if only they could match smartphones in some way in terms of functionality.

Kamiki Raichi series
Marumarumarumarumarumarumarumaru Satsujin Jiken ("The ???????? Murder Case", 2014)
Niji no Ha Brush - Kamiki Raichi Hassan ("Rainbow Toothbrush - Kamiki Raichi On the Loose", 2015
Dare mo Boku wo Sabakenai ("Nobody Can Pass Judgement On Me", 2016)
Souja Misshitsu ("The Locked Rooms of the Twin Snakes", 2017)
Mailer Daemon no Senritsu ("The Terror of the Mailer Daemon", 2018)

The attractive red-haired Kamiki Raichi is one of the more unlikely detective characters you'll come across. Of course, the fact she's a senior high school student who loves playing amateur detective isn't that strange on its own: we have enough examples of that. But her main source of income might be reason for some raised eyebrows, as she practices enjou kousai, or "compensated dating". In theory, this means that older men are paying younger, attractive women for their companionship and in practice, and also in Raichi's case, it means she's prostituting herself and she's good at her job. She has a few "regular clients" who visit her at regular intervals in her own luxurious apartment, one of them being the student Jin. One day, he shows Raichi a strange e-mail he received on his phone with the message "You will die after one week," sent by the "Mailer Daemon". It was sent one week ago, meaning that Jin's supposed to die that very day, but they don't think much of it, and after their usual private time, Jin leaves Raichi's apartment. He is killed on his way home however, and Raichi vowes to find out who this Mailer Daemon is and to avenge her client. She learns from the police that the Mailer Daemon had struck once earlier: a female office worker had been killed in her own apartment, and she too had received the same e-mail. The one link between the victims is that they both still used old feature flip-phones (garakei) from the service provider X-Phone instead of smartphones. While Raichi's investigating the case, she also learns that Inspector Aikawa, one of her "regular clients", wants to resign from his job after previous events (see: Souja Misshitsu) and has now gone off somewhere, so she now also needs to help her old friend in Hayasaka Yabusaka's Mailer Daemon no Senritsu ("The Terror of the Mailer Daemon", 2018).

It's been four years already since Hayasaka Yabusaka's debut with the first adventure featuring his self-prostituting Raichi, and this series has remained quite unique within the wide mystery genre due to its use of sex as vital part of the mystery. In most mystery fiction, sex is only used to spice things up if it appears, but in the Kamiki Raichi stories, sex is an integral part of the core mystery plot. The descriptions of Raichi's sexual adventures might seem a bit graphic at times, but they are always there for a cause: they contain vital hints to solving the crime or link up to the mystery in rather ingenious ways and the mystery wouldn't work without those scenes. Mailer Daemon no Senritsu is graphically quite tame compared to the first two entries in the series by the way, but you definitely need to think a bit dirty if you want to have a chance at solving the mystery of Mailer Daemon.

Each of the previous three novels were obviously written around their respective, major twist solutions. I can easily summarize each of the previous novels with "oh, that's the one where XXX", and you'd instantly understand what I'm talking about. What Hayasaka did well for each of these entries was working these single ideas out to full-fledged novels. Mailer Daemon no Senritsu feels quite different as a mystery novel, because this time, there's not really one major twist that explains most of the happenings. Instead, this novel is packed with a lot of smaller ideas and mysteries to be solved. What I found disappointing was that the various ideas didn't seem to connect well, and at times Mailer Daemon no Senritsu felt quite disjointed, even if it had a few good ideas. The first half of the novel has some short, but pretty interesting situations. The locked room murder in the prologue is excellent: it is only a locked room murder in the eyes of the victim, as she's suddenly attacked in her apartment room even though she made sure there was nobody in the room save for her dog. The police swiftly figures out what happened, as does Raichi, but the simple locked room mystery is both smart and really quite what you'd expect from the Raichi series, as it preys on the reader (and the victim) to make a certain assumption. Near the half-way point, there is another death that is first assumed to be a suicide, but soon proved to be a murder: this one is fairly simple, partly due to the good clewing in the novel, but it's also a highly original concept to use in mystery fiction. The circumstances are slightly unique to Japan perhaps, but it's a good example how to use modern technology in puzzle plot mysteries set in this age.

The second half of the book revolves around Inspector Aikawa, who's staying in a strange pension in a small fisherman's village. He learns that Raichi's involved with the Mailer Daemon case and that she tweeted extensively on a certain day, when she was observing the four main suspects of the case while they were viewing a certain theatre play together. The other guests in the pension turn out to be acquaintances of Raichi too, and spurred on by the Challenge to the Reader tweet Raichi wrote, the group decides to try to find out who the Mailer Daemon is, based on the tweets of Raichi made during that theater visit. This part really feels disjointed from the first half of the book, as the pension guests focus solely on the tweets from the theater now. It is an interesting part, with each guest adding a bit of their own to the solution, but once again, the mysteries here are more like a series of minor, not directly connected ideas rather than a well-structured whole. There are some ingenious parts though: one idea makes brilliant use of the way Twitter works for example and it is quite amazing how this part was written. As always, the solution also depends on some erotic aspect of the story, and while the initial reveal was pretty good, I thought the actual explanation of the how and why this came to be was a bit underwhelming. The motive for the murders too is at one hand understandable in a real-world manner, but would anyone go as far as murder to accomplish this? In the end, I felt that Mailer Daemon no Senritsu had its share of good ideas for mystery plots, but they didn't always worked well together to form one consistent novel, and perhaps they would've done better as single ideas in short stories, rather than thrown together.

By the way, while Mailer Daemon no Senritsu can be read without any knowledge of this series, I'd strongly recommend you reading this one as last. I don't know if Hayasaka has concrete plans for Raichi's future at this moment, but for now, it seems Mailer Daemon no Senritsu is written to be the final part of this first "chapter" of the Raichi series, spanning four novels and one short story collection. Mailer Daemon no Senritsu is brimming with references to the earlier stories, and there are also quite a few guest appearances from the other novels/short stories, who all help out a bit in solving this mystery. Heck, even Hayasaka himself makes a guest appearance (in a television show)! The whole novel is filled with fanservice, so it's really best to read the previous stories first and the ending of this novel seems to suggest that we are at least not likely to see the secondary cast from the last few novels (like Inspector Aikawa and his subordinate Komatsunagi) any time soon again. Speaking of the cast, the names of the characters this time are pretty awful in a fun manner (everyone basically has a Very Literal Name, like Raichi's client having the character for "customer" in his name).

I have to admit I find it hard to make up my mind on Mailer Daemon no Senritsu. It doesn't work nearly as well as previous novels as one consistent, well-plotted mystery story, but it has some really good small ideas in it (I love the locked room murder in the prologue) and it also makes fantastic use of original fields in mystery fiction, especially modern technology like smartphones, Twitter and the garakei flip-phones. The many guest appearances and the packed plot make for a rather hasty story that feels a bit light, but it's certainly an entertaining read for those who have followed Raichi's adventures until now, with lots of fanservice. The ending seems to be saying Raichi will be taking some time off to find new clients, but I do hope that Raichi will return in a future novel, because I certainly still haven't had enough of her!

Original Japanese title(s):  早坂吝　『メーラーデーモンの戦慄』