Minor spoilers although I don't think this show is necessarily hiding how it plans to end, it is very much about the journey.

Animation

The show was animated by Doga Koba, which is a generally respected studio, or at least it was in 2015. I'm not one to usually catch these things but there were a few noticeable animation errors here and there. The action scenes weren't outstanding but they were fine. Background art was good. This show had a slightly below average amount of talking heads for a slice-of-life.

Story

If a story is a three-legged tripod between setting, plot, and characters, Plastic Memories is more of a duopod or something. The amount of meaningful exposition and setting given is nearly zero, just enough to fulfill a little bit of explanation and aesthetic goals. How long have people been living with giftias? Why do they have such a short and precise lifespan? Is the company even trying to improve that? If a giftia is an android, why can't one just be copied into a new body? It makes for unclear and confusing stakes and it feels like this giant hole of "because the writer said so" in the story. The stakes become a bit more solid during one of the middle arcs when a giftia exceeds her expiration but it still feels ungrounded. Perhaps it could be argued that it leaves the truth of the ending up in the air until it finally happens but I think it's pretty clear what's going to happen from maybe even the first few scenes of the show.

Part of the reason for this I think is that this isn't really a show about androids or AI or even anything metahuman. Gifitias are simply an excuse for having characters with short, determined lifespans and also fills a little bit of an aesthetic goal. They are mentally and physically (most of the time) identical to humans and they are treated exactly like humans, with the exception of termination. I think it's maybe a bit odd to introduce this situation with potential for a lot of complexity and not really delve into it but again, that's not what the story is interested in and I can concede that.

Plot and characters fair better in this one. The show is mostly character driven so plot only comes in for a few situations and the final conflict of the story. I think Tsukasa and Isla are fine characters but it would have been nice to see more sides of them to round them out. I think we see more change with Isla as she warms up to Tsukasa but I wish we saw more with Tsukasa, especially how his character changed after the end. Other characters have a tendency to be a bit more troupe-y but for the most part are executed well enough with a few memorable moments, such as Constance's moments of wisdom or the crazy playboy senpai.

What really pulls Plastic Memories together is its ending. It doesn't waver in its commitment and the final few episodes are a heart-wrenching build up to a sweet but painful ending. A happy ending would have been some nice fan service but I think this show is memorable for its brave commitment to its main idea of "If my lifespan was predetermined, how would I handle that?"

I don't know if there is enough here to stretch for 24 episodes but a few more would have maybe allowed for better exposition and improve the pacing and development of Tsukasa and Isla's relationship.

Sound

I wasn't paying a lot of attention to the soundtrack on the my first watch-through so I'll have to come back after another and flesh out my thoughts here. The opening song is especially good, almost never skipped it. The incidental music seems well-placed and thought out and gives a lot of moments silence which is important for a show like this. Overall, it's functional but not very memorable.

Conclusion

Plastic Memories frames its story under a thought-provoking question and then sets off to demonstrate what it means. It has some clear flaws but I think the way it pulls it together for the end will leave an impression on most of the audience.