Skip to 0 minutes and 4 secondsWe have already looked in some detail at the five main types of binding, so here I would like to say a few words about some of the more unusual ones. Let us start with this book. As you can see, it has a cover but no spine or bound area. What you do is open it up like this. Although it is too big to open it completely, it is a map of Kyoto. This format was used for oversized items, such as extra-large maps or board games, and it is known as tatamimono (fold-up books). Usually, the cover was applied to the outermost layer of the folded-up sheet to make it more resistant and durable. Take a look at this book.
Skip to 1 minute and 28 secondsYou can see thread here, so at first sight it looks like a fukurotoji book, but where you would expect to see a crease there is none. And neither there is one on this side. In this kind of books the leaves were simply stacked and sewn together without folding them. It is perhaps the simplest method imaginable but actually it is quite rare. Despite the unusual binding, this is a sturdily-made book and it was in this format from the start. On careful inspection, the number of extant specimens is not so small, so the method must have enjoyed some degree of popularity. Next, let us consider two unusual ways of applying the cover to a book. First, look at this book.
Skip to 2 minutes and 34 secondsYou can see a cord is visible near the binding. If we turn the book, this is what the back looks like. Two holes are made on each of the two covers and a cord is passed through them which is then tied in an ornamental knot on the front cover. This is called musubitoji (knot binding). It was previously known as Yamato-toji (Yamato binding) but as this may lead to confusion with tetsuyōsō binding (which is also sometimes called Yamato binding due to its popularity in Japan), the term musubitoji is used instead.
Skip to 3 minutes and 29 secondsThis book here is bound as a fukurotoji, but older books tend to have the crease on this side, like tetsuyōsō books, so the name musubitoji describes the outer cover, not the binding as such. Another case is what you see here. This particular book was in fact made in China, but the cover was added in Japan. What's distinctive about it is that usually bound books have two covers, a front one and a back one, but in this case a single piece of material is wrapped around three sides of the book serving as front cover, spine, and back cover, It is especially noteworthy because it can be seen in relatively early, Muromachi to early Edo-period, books.
Less common binding methods
The video introduces the less common binding styles. Read the article below and watch Prof. Sasaki talk about them.
Tatamimono (fold-up books)
The fourth of the less common formats is the (d) tatamimono (fold-up books). Several sheets of paper are joined together to form a single large sheet, which is then carefully folded both vertically and horizontally to close it. Once folded, the covers are applied. (See below)
This format was used for maps, diagrams, and board games like sugoroku. Tatamimono are counted in ho.
Tan’yōsō (“single leaf” binding)
Another rarer format is the (c) tan’yōsō (“single leaf” binding), which consists in joining together whole sheets without folding them. (See below)
Although it would seem to be the simplest of all methods, it never became popular. The covers are sometimes applied with thread, as in the fukurotoji, and sometimes tied according to the musubitoji method, so it’s impossible to tell the binding without looking inside.
Musubitoji (“knot” binding).
Some of the less common formats must also be mentioned. The first is the (a) musubitoji (“knot” binding). Rather than a distinct type of binding, it is probably more accurate to describe it as a particular way to apply the cover to the book. Pairs of holes are opened on both covers near the spine and bundled thread or string is passed through them from underneath the spine and then tied in a knot over the cover. (See Below).
It is very decorative, so it was used on both fukurotoji and tetsuyōsō-style books. Its use is documented as early as the 12th century. It is sometimes referred to as Yamato-toji (Yamato binding), which is also another name for the tetsuyōsō format, so caution is needed when using the term.
Hōhaisō (“wrapped-spine” binding)
Next is the (b) hōhaisō (wrapped-spine binding). Instead of the usual two pieces for the two covers (front and back), a single piece of material is wrapped around three sides of the book serving as front cover, spine, and back cover. (See below)
 Example of Hōhaisō: Embun hyakushū [One-hundred Poem Sequence of the Enbun era]. Click to take a closer look
In some items, only the area of the spine is wrapped with the outer layer of paper. This method seems to have been particularly popular in the late Muromachi period (16th century). In terms of how to count such items, the best policy is to look at how the paper is joined together.
Summary of Binding Styles
To sum up, Japanese books come in many different formats, which were used according to the book’s content and purpose. I have already noted that scrolls were the most prestigious format, but it is worth adding that, especially in the case of beautifully written items made with superior quality paper, their value for textual research is also very high, as they tend to preserve the most accurate and precise version of the text. Book-style formats, on the other hand, tend to be less textually reliable. That is not to say that they are always necessarily poor from a documentary point of view. Even fukurotoji books, which were arguably the least carefully produced, were sometimes made under the direct supervision of the author. The point is rather that if books come to us in different bindings, we need to consider why they do and what the binding may tell us about the nature and content of that book.