[Contains ending spoilers]
I can see the point Ogawa was trying to make with this book, but I found it to be a really unsatisfying read. The ending was interesting on it's own, the idea of a person slowly disappearing until they're nothing but a voice remaining, but there are so many introduced plotlines that go nowhere and so many story elements left unexplained. Who actually are the memory police? What are they gaining from these disappearances? How are they unaffected by them? Who's controlling them and the island? The disappearances are also insanely inconsistant - when the roses and books disappear they're all intentionally destroyed, but when boats disappear the boat is somehow allowed to just stay moored up untouched? The memory police stormed the narrator's house to look for books and birds, yet they were fine leaving the boat out in the open? Why the inconsistency?
If you are reading this book for a commentary on authoritarianism like it appears to be, go find a different one. The memory police are hardly even explored, and when they do they just regurgitate examples of real life authoritarianism with no explaination of their goals. There isn't even a direct confirmation that they're responsible for the disappearances other than a vague quote of a character theorising the island is "controlled by men who want to see things disappear". It feels as if the author wanted to have them be the main antagonists but didn't follow through with it, so they're just kind of there terrorising citizens while the true threat of the book is the disappearances themselves. I don't know. I was invested in the concept but the execution really sucked.
Ogawa should have picked one of 2 storylines - either the disappearances are the biggest threat, or the memory police is. She tried to have both, and it ended with a lackluster story where neither storyline is entirely satisfying.