Himawari no Sakanai Natsu (roughly 'The Summer When the Sunflowers Don't Blossom') follows a schoolchild, Michio, as he attempts to solve the mystery of his friend S-kun's death. When S-kun is absent on the last day of school, Michio volunteers to take his homework to S-kun's home, only to find him hanged with a brutally murdered cat on the way to his house. But once the police arrive at the crime scene, S-kun's body is long gone. Though this isn't like your average mystery, where it's the detective's job to figure out the whodunnit, because S-kun is reincarnated as a spider and tells Michio about his last moments. Shocked to hear about his missing corpse, he then asks Michio to tail his murderer and discover the whereabouts of his corpses. Or at least, that's what the story seems to be at first.

Though this seems to be a straight mystery at first, it is sometimes recommended as a horror novel, and for good reason. While I still wouldn't consider horror its main genre, there are enough elements of psychological horror in the story, particularly in the last third or so, to appeal to horror readers. In fact, even before the protagonist discovered S-kun's death, the writer spent quite a few words describing the protagonist's terror and paranoia. While those descriptions were not the best in my opinion (there was, in particular, one weird change of mood shortly after the discovery of S-kun's body), it's pretty brilliant if you think about it again after reading the ending.

The bulk of the book (after the day of S-kun's body's discovery and before the final third) mainly has mystery and occasionally thriller elements. Descriptions of crime scenes are largely matter-of-fact, and not written to horrify or disgust. Because the protagonist (and reader) already know who the killer is, the main focus is on where he hid the corpse, and how. I don't really know how to comment on mysteries, so I'll leave that part out, but I enjoyed the two close calls he had when trying to tail and accuse the killer.

The psychological horror really began to set in after a conversation between the protagonist and the victim's mother. This is the point where the protagonist begins to behave strangely, as if seized by bouts of madness and paranoia. There are also many horror segments from the perspective of the deuteragonist, an old man living near S-kun's house, which I thoroughly enjoyed. The last 10% of the book throws a series of plot twists in the reader's way. I'll admit that I found the first couple of twists pretty forced and artificial, as if the writer wanted to surprise the reader just because, but the ending more than made up for it by revealing how they connect to the main theme of the book.

The characterisation was not bad for a book of its length, but could have been better. The protagonist isn't a bad character, though he didn't seem to have that much of a personality till near the end. The deuteragonist's character was similarly unclear before the end. Considering how smart and quick-witted S-kun is shown to be, I'd be curious to know why he was the subject of extreme bullying and ostracisation, but this is never really discussed. Mika, the protagonist's sister, has a lot of screen time, and is shown to be a very likeable character, but she seems waaay too mature for her age to be believable - I doubt many thirteen-year-olds can act like that, let alone a three-year-old. The protagonist's mother is characterised very successfully as an utterly despicable person; however, there's also a minor point about the mother's characterisation that isn't adequately explained to me, and seems more strange than anything. (I can't say much more about the characters without huge spoilers; let's just say the reveals alleviate some of my complaints about the characters.)

Overall, while I'm not a fanatic of this book as some people seem to be, it's still a fairly short and good enough read that's well worth your time, particularly if you're a fan of books with (heavily foreshadowed) plot twists.