I can tell why this show has few reviews. I picked it on a whim because I thought the poster was charming, but unfortunately this show is just a whole lot of nothing. A couple of character designs and backgrounds are nice, but everyone in the show is as flat as a board, with a singular personality trait defining them for nearly the entire run. Now, this wouldn’t be much of an issue if the mysteries were engaging, but they're just as shallow as the rest of the writing, taking the place of filler, detracting time from the things that actually matter to the plot and characters. There's legit no reason to watch this anime, which pains me to say because I REALLY tried to like it.
There's a lot of questions surrounding Mayuki: Why does he live in a western styled mansion in Japan? Why is white haired Hatsune Miku after him? Why does he go galaxy brain when he drinks tea sometimes? Where are his parents? Why does his butler turn the maid and the older sister of a friend into battle automatons (or as the show calls them, Aya)? Why is every single girl mildly close to his age in love with him? Well, I can safely say, that there will be basically nothing surrounding the answers to these questions until episode 14. None of the initial, smaller mysteries add anything to the overarching plot, which is asinine for a 26 episode show. Mayuki and Seiran are easily the most interesting characters by default, but it's hard to keep that interest if almost every episode is spent spinning the wheels and getting nowhere. The core of the show's plot also has basically nothing to do with Mayuki's school friends or the detectives, so once you find that out, it feels like your time has been wasted with all of the focus that's been put on them. The ideas presented later on when things FINALLY get going are extremely interesting, but they're bogged down by too many faces and not enough to do.
When you have a mystery show, either you need engaging characters, thought out mysteries, or both. (in the best case scenario) This show has neither. If a character is introduced in the episode, and they aren’t the victim, chances are they're the perpetrator, and they're being mind controlled by the villain. It's hard to even consider what happens mysteries because they're either so obvious, something that audience can't possibly solve, or the show bends over backwards to get the mystery to work. (for example: a firefighter making an ice ladder just to impale a guy on a radio tower because the guy found out the firefighter was stealing things from buildings HE set on fire.) A good ⅔ of this anime could be cut and nothing would be lost. Honestly, I don't even know why it's a mystery show when the actual mysteries to be solved are nothing but filler level writing.
Another wasted opportunity is the setting. I'm a big fan of overgrown, dilapidated buildings, so it takes real effort to not make them interesting to me. If the setting was replaced with any other anime that takes place in vaguely futuristic Japan, there wouldn’t be anything missing. It hardly explores the main core of its environment, that being Tokyo becoming ruined in the wake of a natural disaster (caused by something story related at least), and what that potentially did to the entire country. It's like everything about this show was on a dart board and was chosen at random, nothing is cohesive or thematically resonant.
Sad waste of intrigue...