I definitely don't watch or enjoy sci-fi anime of this type very often - it's rare for any of them to capture my interest. The plots are somewhat recycled, the characters typical - and for the record, I'm not claiming this show is any different in some ways. Nevertheless, despite the criticisms I have about this show, I found myself being swept along and enjoying it to the fullest, or as near as possible.
In terms of story, it definitely grabbed my attention from the very beginning. I enjoyed the standalone mysteries of the first few episodes the most by far, but I also thought the way each mystery and murderer was connected to the Big Bad in the end was overall well done. I certainly don't think every detail made sense and every other episode I found myself lost over some small fact or another, but as I continuously emphasize when it comes to anime, I would much rather prefer to feel a little lost than have secondary characters breathing down my neck to explain every little element of a world or a clunky narration doing the same. In this case, though this didn't always occur, sometimes unknown and seemingly altogether unimportant details were in fact explained later in the show and I really liked that - it, among many other small threads, created the feeling of a throughline in the plot that I appreciated. ID:I was also great at drawing parallels and coming full circle - for example, though the climax felt a little anticlimactic, it took place in the first serial killer's mind Narihisago ever visits, which filled out the gaps in the somewhat easy solution.
I still haven't made up my mind when it comes to the art of ID:I. I kept going back and forth between loving it and cringing at it - the beauty was really in the details, I think. Closeup shots and character designs (Sakaido's in particular is maybe one of my favorite character designs ever (minus the Natsu Dragneel-type hair?) and I still don't know why) were all great, and the moody, subtle color palette was perfect for the show. I also loved all the designs of and concepts behind the various ID wells, they never disappointed there! But admittedly the style was a little simple and, from farther away, pretty "lazily" done. I don't know what this show's animation budget was, but I wish they'd had a higher one so I could have seen what the art could have looked like at its full potential. I'm rating it a 7 because I definitely enjoyed it for what it was, but I know it could have been even better.
I don't have much to say about the sound. I enjoyed the tense violin sprinkled throughout, but the opening theme song wasn't my favorite. I also felt the songs with lyrics sprinkled throughout were completely misplaced - I didn't like any of them and all of them, particularly the emotional one played over a montage of Narihisago and his family, all but wrenched me out of the immersion of the show, leaving me feeling more irritated than excited, inspired, or sad.
I'm a sucker for a show with good characters and these characters kept me invested from start to finish! Narihisago was the perfect broken, vengeful main character for me - he was exactly what I want from a protagonist like that. Tsuda Kenjiro is one of my all-time favorite seiyuus and I have to give props to his work with this character (and every character he plays, honestly). I also really liked Momoki and the strength of his connection to Narihisago. He felt very human and relatable and I liked that his faith in his work and his friend/former colleague never faltered (plus, Hosoya Yoshimasa! Hello!). By far, however, my favorite characters in the show ended up being Hondomachi and Fukuda and that was something I absolutely never could have predicted. I had low expectations for Hondomachi, expecting her to be a Tsunemori Akane-type character - Ps*cho-P*ss fans don't sue me, I was just never impressed with her writing and found her to be a somewhat passive main character which happens to be my least favorite kind. But Hondomachi was one of, if not the, smartest characters on the show - beyond that, she was unreliable and her state of mind was often questionable. She was unattached to people (most people, at least) and didn't think twice about taking her own or others' lives if the situation called for it. I feel like I've almost never encountered a character like her but I'm so glad I found her in this show! Her relationship with Fukuda was another unexpected plot element that never ceased to fascinate me, along with Fukuda himself. Their connection through their respective head holes was just so unique and utilized really well, in my opinion! And Fukuda himself, though a terrible person in nearly all respects, became someone it was easy to sympathize with by the end of ID:I, regardless of the tricks he pulled. Additionally, I appreciated the side characters' innate cleverness and immediate understanding of every situation they faced - no singular mastermind surrounded by idiots here. They all held their own!
I enjoyed this show greatly in no small part because I was able to suspend my disbelief and let it play out without allowing my critiques and unanswered questions to get in the way of my interest. If you're unable to do that, I don't think this show is for you. There were many, many little details that stopped me in my tracks momentarily to think "Huh, is that actually physically possible?" or "How could anyone make that leap with that amount of information?", but because I let these questions go in favor of hearing and seeing where the story went with itself, I was able to quickly forgive the faults in favor of the nuanced and intriguing conversations and themes the story is full of regardless. I totally understand why anyone might not be able to do the same, but it's important for regarding the show in a positive light, in my opinion.
To summarize, this show was a fun mystery/thriller that passed an otherwise empty afternoon really well. If you're willing to set aside some instinctive logic and disbelief and watch it, I guarantee there are a cool story and some great characters in store for you.
