This isn't a horror series, but it hit me with a greater sense of existential dread than anything I've seen before, anime or otherwise. It all comes down to the execution of the main premise. Three siblings are offered the chance to earn a million yen simply by pressing a button. The catch? The instant someone pushes it, that person will be transported to an empty, infinite space where they will be trapped for 500-million years, unable to sleep or die. Once the time is up, their memory of those years will be erased and they're returned to the instant they pressed the button, sosubjectively it will be as if they never left. The series explores how each of the siblings perceives that deal and its implications, what happens when they push the button, and some variations on the deal that raise other interesting philosophical questions.

If that sounds rather dry, it isn't, since it's mixed in with some goofy comedy sketches. Most episodes hit you with deep questions in the first half and then decompress with the VAs playing weird improv comedy games in the latter half. The first half of each episode it usually the highlight, while the latter half ranges from hilarious to boring from one episode to the next.

It's also worth noting that this is the cheapest, jankiest-looking CG anime ever made. Ex-Arm looking like Avatar by comparison. A lot of it is clearly shot in real-time using VTuber software. It seems to be rendering on a potato, so there is frequent slowdown and models clipping through objects. It's literally the kind of thing that would be more at home on Youtube than Prime Video, and is obviously a one-person show aside from the VAs. The cheapness also doesn't really matter, since it's able to convey the situations clearly, and the surreal style of much of it means the jank just enhances the show's creepiness.

Overall, it's an experience completely unlike any other show.