1) Preparation
Preparation process can be further divided in six categories, including 1) Selection of wood, 2) Measuring, 3) marking wood, 4) sawing, 5) Curving to make soundboards, and 6) drying sound boards.
The size of Koto, including the numbers of strings that go with is the major factor on deciding what types of wood to be used.In general, Kiri (paulownia) is preferred for making Koto for its density and weight. The wood need to be more than 60cm height, and its age is over 20 years old. In Japan, those woods can be found in Nigata, Akita, Fukuyama, and Fukushima prefectures, and also, they can be found in northern countries such as China and Canada. Depending on the grain of the wood, the numbers of soundboards that can be taken from a wood differ. In addition, the outer part and core part of wood are considered inappropriate materials to make Koto. After finish marking the wood to be cut, each piece of the board is curved to shape like Koto, and also, they require to be sundry for three to five years before actually putting all parts together.