I spent nearly five years "trying" to learn kanji, while living in Japan, and I just couldn't do it. This book literally changed my life. We'll avoid discussing my learning pace, but I can say this book provides the absolute best way to actually learn and remember kanji. If you read it carefully from the first page, and follow the author's instructions on "how to study", I can guarantee you will not only learn, but also remember them well. The "4 kanji per page" style is fantastic, as it sets a virtual pace for you to follow (ex: 4 per day). Each kanji provides a reference to similar-looking kanji, so at no point will you skip one thinking "oh, I learned this already". The author takes time to explain subtle differences between similar kanji, which is really helpful when everything starts looking the same.
One small point that wasn't mentioned by others, are the appendixes at the back of the book. They contain lists of kanji sorted in different ways (sorted by radical, sorted by stroke count, sorted by kana/sound, etc).. this makes looking up a kanji much easier, and it also allows you to see them surrounded by other kanji with identical sounds, or identical stroke count. Honestly the individual kanji pages would normally be sufficient, but the effort put into the appendixes/indexes at the end of the book (which span nearly a hundred pages) makes this book invaluable for anyone who's serious about learning kanji. The learning order is exactly the right way they should be learned, and the author deserves much praise for having designed it that way.
I used this book to improve my knowledge of kanji over the few hundred that I already knew before starting. I used it over the course of some months to get to a place where I can comfortably read just about any kanji I come across and at least know how to read it, if not guess at the meaning. The mnemonics are fantastically well-thought out and, though the aim of this book is to improve reading comprehension, I found it easy to use the mnemonics to teach myself to write all the kanji in the book as well. Using space-repetition software to review the information in the book, within a relatively short time I was able to feel like I finally was able to overcome the kanji-barrier and start reading books in Japanese.
I can't recommend this book enough. It has turned into the cornerstone of my Japanese self-study.
If you're starting out with kanji you've probably heard of a lot of popular books for just that, but this is without a doubt the best one. Here's a few key points why you should buy this;
1. The kanji are listed logically so that similar looking kanji are learned at the same time. This prevents confusion later since you won't come across kanji that look like ones you already learned.
2. The book doesn't introduce new graphemes and radicals at lightning speed. It introduces them gradually so you can construct kanji from images you know rather than having to constantly remember new ones.
3. Every kanji has its own unique, well-written mnemonic to ensure you remember the meaning.
4. Unlike some other books, this one will teach you Japanese vocabulary and pronunciation alongside the kanji.
In short, if you're serious about kanji, this is the book that will get you to a strong level. Completing the book in its entirety will enable you to understand the core 2300 kanji as well as over 10 000 unique Japanese words.