It's actually quite difficult to place this text. Is it a religious text? A novel? An extended poem? A diatribe? An instruction manual on 'cha no yuu'? Ironically (given the title) it is more of the former and less of the later.
Those seeking a book to 'explain' cha no yuu may well be disappointed, then again they may not. One truth about this book is this, that every person who has an in interest in Japan, Japanese culture and of course cha no yuu should adopt this book. Read it carefully and slowly (no more than a few pages a day). Highlight the important points and keep it as your constant companion.
I also recommend every Japanese national buy a copy to, find out where you started on the path, where you left off and got lost and try to use it as a map to get back to the Way. In that regard it is the Japanese who are dying of thirst and need to drink at the fountain of knowledge to quench their parched throats and fill their empty stomachs, which for so long have echoed hollow with the sound of emptiness.
If there are minus points to this text is it has to be Okakura's constant digressions in the early chapters, his stumblings, mumblings and banal pre-suppositions pertaining to the imperialist notions of 'Occidental' versus 'Oriental', but then what could one seriously expect from a text penned in 1906. Thankfully to correct these errs and bring the reader back to the path, Sen Soshitu XV takes the reins and provides an invaluable 'afterward' steering us back on course.
N.B. I recommend this bi-lingual version over others of the same text, for numerous reasons. The main one being that as a student of Japanese one can quickly clarify 'kanji', pronunciation or indeed any queries pertaining to the translation by simply checking the facing page - you're effectively getting two books for the one price. Besides that, on a minor point - the book contains some superbly atmospheric monochrome plates. Finally, unlike European paperbacks, their Japanese counterparts are printed on quality stock - not that horrible grey pulp.