Takasuka Katsushi, a young man lacking certain memories and Itsukinomiya Mei, a girl that closed her heart, meet on a cram school's rooftop. He feels gravitated towards crime scenes and takes photos of those while she seems like a living corpse wearing huge disconnected headphones. They soon wind up in solving various mysteries happening among the students at the cram school.
After finally reading more by Mori Hiroshi I realized Mikumo Gakuto must have been inspired by him to a huge extent when he wrote 海底密室. Not even because of the setting or the locked room trick, just because of certain themes and aspects in the dialogues. But then again he did win an award for the SF-mystery he had written before that and he certainly did a good job on the work that I've read and inspiration is not a bad thing at all as long as it does not shift into copying. So to clarify for myself that Mikumo is capable of writing in general, I had to read something else by him.
Here we have 5 consecutive short stories. The first deals with a matter where I'd even question if it can be called a mystery, especially due to the way it's solved, but in retrospect I just accept it as an introduction to the characters. Not the best way to start this book though but I guess it couldn't be helped. The second story certainly turned out to be better, being a play on Christie's ABC murders that can be undoubtedly considered as orthodox. What's to be mentioned about each of the actual cases though is that due to being integrated into a short story there aren't that many suspects, which can make the solution easier but most of the time it really is more about the tricks themselves. This especially applies to the third story where the culprit actually jumps right into your face as long as you figure out the trick. The fourth story tries a bit too hard in my opinion and ends up stretching the reader's suspension of disbelief a bit too much. In various ways. If you're fine with some of that suspension the deduction is certainly fair and possible though. The last story reminded me of the type of trick Mikumo also used in his other work I've read. The hints are dancing around you but you just can't come up with the solution as long as... you don't even know something like this existed in reality. Whether a trick like this would actually work is another question but as long as you're willing to mix a bit SF into it you could come up with the solution I guess. Furthermore this final story also rounded up the characters and the underlying theme of the book pretty fine I think. It's nothing utterly great but somehow you feel like Mikumo constructed everything quite intentionally and dedicated for this final trick of the book. Especially taking into account the format of consecutive short stories I like that the strings somehow merged metaphorically at the end despite of that.
All in all, while the stories were more like puzzles than whodunits most of them work out as pretty orthodox and after the conclusion there's always this kind of melancholy aftertaste due to certain depictions of human relationships. Which would have been even more penetrative and meaningful if those plots where used for a whole book in a more detailed execution. This is the one point that might always bug me while reading short stories: There just isn't enough space to flesh out the different characters and/or just let them talk more about what happens which would have made the outcome of the various stories more interesting. I do have to commend though that the characters Mikumo created this time worked out a little better than Yutori in his other work. While she seemed to have a huge background plot but ended up pretty chopped at the end of the book, Suka and Mei aren't that interesting to begin with, but therefore the book also feels more rounded down. So you somehow have to decide between rounded down but not utterly impressive or kind of chopped up in the end but with a more tangible and significant impact. I hope Mikumo will manage to find a compromise someday, since I can not deny he has a certain talent in augmenting mysteries and science-fiction with underlying themes. He just has to make them a bit more penetrative and impressing.
I do have to admit though that although 海底密室 impressed me more in retrospect, there were also some parts that dragged due to the SF-aspects. 少女ノイズ on the other hand was a really easy read where you are rewarded consecutively in small doses, which in turn hinders the book from being significantly impressing in retrospect. Nevertheless due to its structure I can certainly recommend it as an enjoyable read for when you're on the way to university, work or whatever situation where you don't have that much time but need something against your boredom.