The cover art is apparently just based on the title of today's book, but it's a shame it didn't try incorporate element from the various stories included more prominently, because I like the comic-esque style...
The opening story Kuroi Achilles ("The Black Achilles") is set at Kokonoe High School, where Kousuke, Eimi and Yuki (whose father is police inspector) have formed a little detective club. You'd think there wouldn't be many myseries around an ordinary school, but one day after school, they are witness to a daring robbery: a masked figure snatches a thick envelope from a student and makes a run for it. The victim cries the envelope has all the money members paid for the upcoming trip of the Badminton Club, so a group of students run after the thief. When the thief takes the path up the hill surrounding the school, they think they've got him, but to the chasers' great surprise, the thief leaps off the hill,, only to land safely on a mat prepared on the roof of one of the school buildings. The thief quicky pulls the mat away and makes their escape through the school, while the group of chasers has no choice but to take the long way around back to the school grounds, but it's too late of course. To prevent similar thefts, rules are changed so clubs have to collect money from their members for trips in classrooms under the supervision of teachers, but despite these precautions and the presence of a police detective, the thief strikes again! Like the last time, the thief's escape route leads to the path on the hill, but this time people are of course prepared for his leap back to the school building. The thief however keeps on running up the hill, but just as the chasers manage to come closer, they're in for another surprise: the thief had prepared a zip-line leading from the hill into the empty warehouse right behind the school. Once again, they have to take the long way around, but as the warehouse is locked from the outside, they are sure they have their thief now. But inside they find a dead thief, stabbed with a knife. As the warehouse was locked until the police arrived and the only "open" entrance was the window several meters up the ground from where the thief zipped inside, it seems nobody could've killed him.
This is a fantastic story considering its length. It's not an extremely long short story, but so much happens within its limited page count, complete with false solutions. It's also surprisingly densily clewed, with many minor hints that ultimately explain who committed the murder, which also helps you figure out how the impossible murder in the warehouse was committed. The clewing that leads to the murderer is definitely the highlight of the story: it's classic Queen-style plotting with a lot of clues that point you to specific characteristics the murderer must answer to, but this process plays out across several vectors here, and in terms of information density, it's almost like you've read a story twice the length, even though nothing feels rushed or underdeveloped. I hope this becomes a proper series, because I like the characters and the setting of this!
After an unfortunate accident with their car, Hiromu and his uncle end up at an outdoor log cabin campground in Natsu no Hokuto Shichisei ("The Big Dipper in the Summer"). At dinner they meet most of the other staying guests, but when they return to their own cabin, they run into a horrified woman who says she found a dead woman in her cabin after waking up after her nap. But strangely enough, and to the camp site owner's great surprise, he doesn't recognize the woman who found the body. According to the woman, she's the guest staying in Cabin 2 and when she arrived here earlier this day, someone else helped her at the reception, but the owner says he's the only one working here and that he didn't know about her at all. Whatever the case, the police needs to be contacted, but it's then they find out the phone line's been cut and both the time, weather and the fact that Hiromu's car is lying flipped on the one single road means they can't get help this night. Fortunately, Hiromu's uncle is a former police officer (well, technically, he was in Accounting) and he decides to take over for the moment, but both he and Hiromu are aware that there's something wrong with all the guests and the owner here, and it's clear that the murder is related to their secret, but what?
After the impressive first story, this story was a bit disappointing. This is best read as a closed circle thriller perhaps, as a lot of the story focuses on Hiromu and his uncle knowing something isn't quite right about all the people here and the two of them slowly trying to figure out what's going on and why there was a body left in someone's cabin. There are some memorable moments: the explanation for why the body ended up there is a bit confusing in this medium, but I have to admit I wasn't reading that concentrated so perhaps it would've been more of an "Aha!" moment, but the idea itself I like. The ending also brings things together in an interesting way, giving more depth to a story that otherwise features a bit too much coincidence and people acting in a way that is obviously only meant to facilitate the plot.
Tanima no Cassiopeia ("Cassiopeia in the Rift") has a story-within-a-story structure, and starts with the horror novelist Raitsu Unmo showing his friend Goetsu Akira (a mystery novelist) a manuscript for a detective story he was sent. The story is about a murder committed in a small bar in a tenant building: just before opening hours, one of the female companions working there was found murdered in one of the dressing rooms. While initially, the case looks very simple as only the bartender and the other female companions were inside the bar, while security cameras show nobody else went to that floor around the time of the murder, but a close investigation into the alibis of everyone shows nobody would realistically have had the time to commit the murder after the victim had gone to the dressing room. While Goetsu is reading the story however, he also notices the story he's reading is very similar to an acual murder case that happened a while ago, and he starts investigating the real case too, which leads to a surprising conclusion. This is definitely the other highlight of this volume. This is again a densily plotted story, with the "story-within-a-story" featuring a seemingly straightforward semi-impossible murder set inside a small bar, but once again Amon shows that it's possible to write complex, well-clewed mysteries even with simple settings and it should come as no surprise that the story-within-a-story structure is used to add an extra dimension to the puzzle that really makes this a memorable read.
The final story, Byouin no Ningyohime ("The Mermaid Princess in the Hospital"), is set at an university hospital, where a female nurse was found dead, having fallen from the rooftop of the lab building. Yukari, who works at oral surgery, was practically witness to the death, as the victim fell right behind her, and it turns out she knew the nurse too. At first, it was assumed she committed suicide, but soon after the police learns the victim cried out when she fell of the rooftop, which doesn't seem to indicate a will to die. The curious fact the victim was clenching her bicycle key in her hand as she died also puzzles the police. Murder is suspected, but the investigation quickly shows nobody went on the roof with the victim and that she should have been all alone when she fell of the roof. If this was a murder, how the murderer arrive on the roof and get away again completely unseen? This story didn't quite work for me: it's basically built around two ideas that could've worked alone, but I don't think joining them really adds something to the plot, at least not in a way that provides synergy. The howdunnit aspect of the murder is a bit unbelievable, as it requires the victim to be very very gullible even if I think the mechanics behind the idea are okay.
As my first encounter with Aman Junichi, I think Hoshizora no Palette was quite amusing. While not all four stories in this book were of the same level, the two highlights of the volume are really good and told me I really should read more of Aman. The four stories are quite puzzle-focused, so if you're into that kind of mystery stories (like me!), you'll find a lot to like here, though I have to say that this volume is also quite diverse in terms of story backgrounds, so I think any mystery fan should be able to find something to like here.
