(There's a TL;DR at the bottom.)
The first half of the show presented itself as a silly comedy and slice-of-life kind of show. It was fun, the characters were were interesting and there was a slight mystery behind how the events came to be.
The third quarter of the show maintained the comedy, but added a weird mystery in by adding another character. By the end of episode 9, most people had a good idea what was going to happen.
The last quarter of the show was fucking depressing and almost painful to watch. Episodes 10 and 11 were soul-crushingly downers that completely dropped the fun, comedic part of the show and added in huge amounts of drama. Many will be thrown off by this. The last episode brings things back to a nice-ish ending, but still somewhat depressing when you consider the facts presented in the show.
Now then, the break down:
Story- 8
The story starts off nicely with an interesting premise. A somewhat obvious twist is thrown in which becomes obvious by episode 7 or 8 (that's when the viewer will have probably guessed it) and the twist is revealed in episode 9. Then we get the ultra-depressing last quarter of the show. Story-wise, it's well thought-out, but the finale is a bit unexpected, especially given what we're told about Hina in the show. Overall, I thought the story was very good, but your opinion will vary based on whether you look at it as a "bigger picture" type score, or a "this is how I felt at the end" type score.
Art - 8
The art was very good. It was bright and vibrant with some really nice backgrounds and some interesting attention to details (notice that in the title of the anime, the character for 'Day" changes slightly with each episode as an example).
Sound - 7
The audio was good. Nice background music never really felt out of place, but never led the scene either. No complaints about the voice acting either.
Character - 6
There were some really interesting characters, but there were also problematic moments where characters did things that made no sense just to add to the drama factor (Youta yelling repeatedly for no real reason after he was told not to). Overall, there are no problems with the characters, but there were no incredible developments that made them super interesting either. Aside from Hina, the remaining characters underwent no significant changes. Even though Yoiuta and Izanami changed, their personality shifts felt forced, especially in the case of Izanami.
Enjoyment - 6
This was a show that had a great start and just changed gears way too fast for comfort. There are a lot of great things in the show, but they are hurt by the drastic tone change and the initial ack of direction.
Overall - 7
It's not a bad show, but it's not a masterpiece, either. I enjoyed it for the most part, and I get why the story had the dramatic change in tone at the end. It's certainly not going to appeal to everyone and I feel like many people will hate it solely because it became super dramatic in the last few episodes, but if you watch it through, you'll get to see some great comedy in the first half and some interesting story and heart-wrenching/heartwarming moments at the end.
TL;DR
It's not for everybody. Don't be fooled by the first few episodes--the show flips from light-hearted comedy to depressing drama about 2/3 the way through. A lot of people will be turned off by the drastic change.
The harsh shift aside, the story isn't bad and it's still a decent show overall.
