This review is very vague about the plot, so I don't think there are any spoilers. Also, my overall score is subject to change: my opinion may change once I've thought about it more.
Story and Presentation - 6/10
The plot might sound familiar, or at least the time-traveling part: the main character goes back in time to fix past mistakes. He gets sent back to his childhood to stop the abduction and murder of one of the girls in his elementary school class.
What I liked about the story was the way it was told. I found the pacing and suspense to be quite good. There were a lot of cliffhanger endings, but given that this was a mystery anime, they were appropriate and not obnoxious.
In terms of presentation, there were some dramatic camera angles that I thought were utilized quite well. The character designs looked nice. I can't speak much to the animation and sound quality, since it's not my area of expertise, but I got the sense that this was a well put-together anime. In my opinion, the best parts of the presentation were the ones that weren't thrown in the viewer's face: things being re-incorporated, shots of characters in the background that reveal something about them, using eye color to express a character's emotion, etc.
However.
This anime completely failed at being a mystery. Sure, there were some moments of tension, but they were mostly resulting from curiosity.
My main issue is that this anime was extremely heavy-handed in terms of plot; it wasn't given any room to breathe. I guessed who the killer was early on, so it was difficult to remain invested in the mystery. Normally, that would fine; a good mystery has a variety of possible options. Even if the viewer guesses the ending, new information is revealed, and the viewer doubts themselves as they have to consider alternative possibilities and red herrings. This anime didn't successfully accomplish this. It just continued with the plot without stopping to look at different sides of the story. (EDIT: After reading other reviews, I realize that being a mystery might not have been the main point of the show. However, there was a definite mystery element, which is what I'm talking about here. I'm also talking about the overall plot, since I found it to be heavy-handed as well).
Also, there was a lot of morality bs piled onto the show, especially near the end. I agree that anime can illustrate moral messages, but near the end, I felt like I was watching a shounen fighting series about the 'power of friendship'. The moral bludgeoning made the show less sophisticated and unique; with more developed characters and more subtly, I think it really could have been something great.
It dealt with a fair amount of serious issues, but not with delicacy. I always felt like they served as a part of the story. That's not necessarily a bad thing; an anime can include mature content without dissecting it. However, I found some of the themes to be overwrought and simplified. (I'm not going to specify which themes these are, since I want to avoid spoilers).
Furthermore, I found the time-traveling element to be detrimental to the suspense. Maybe that's just a personal thing, but as soon as a character has the potential to travel in time, I don't take what's happening in the moment as seriously. Time-traveling can be a plot device. It wasn't really used as a plot device in this case, but I would have appreciated more being done with the time traveling element, ie, outlining rules and moral implications.
Character – 6/10
Really, I want to give the characters a lower score. I actually found them to be quite under-developed. However, I'm giving them a decent score given the target audience and genre of the story: this is an entertaining drama, not a psychologically-focused exploration of human nature. The characters, for the most part, played their part well in harmony with the story.
The best thing was that they didn't adhere to obnoxious cliches. (Sidenote: it's kind of sad that “not-cliched” is a compliment). The characters did follow some common tropes, but it's impossible to create a character that doesn't fit into any tropes at all.
The friends had distinctive personalities that, for the most part, weren't overly exaggerated. I was fond of Kenya and Hiromi, though I didn't find them to be very unique. I would have liked to see the story shift a little more to them: they rarely got more development than being “the main character's friends”, despite being quite important to the plot.
I liked the relationship between the main character and his mother, and I'm glad it was a focus of the anime.
The main character himself was relatable, albeit bland. I like how he added some humor to the show, and I enjoyed learning more about him as the series went on. Though, I'm not kidding about him being bland; I forgot his name for a second while writing this review.
The killer's development was good. I appreciated the psychology that went behind it, and they showed their personality well without dragging down the show. Though, I don't think this killer is going to become as iconic as Johan Liebert or other well-crafted anime villains.
That being said, I wasn't particularly invested in the characters. The viewer doesn't get to see many sides of their personality, except maybe for the main character. Essentially, I found them to be well-balanced and leaving a very shallow impression.
Enjoyment - 8/10
I would recommend this anime to someone looking for an enjoyable way to pass the time. It was well-constructed and engrossing, with several interesting elements to the story and characters. However, it lacked a unique artistic vision, complex character development, and analysis of moral issues. I'm glad I watched this anime, though I don't feel as if I've learned much from it.
