Mitsumata belongs to the "Thymelaeaceae" of plants genus family, in the same group with Gampi. The name means "three-pronged", because of its branch shape.
The history as paper material is not very old, likely since around 1700. (There is also another academic report that Mitsumata had been mixed up with Gampi through the history.).
In 1879, the Japanese National Printing Bureau decided to use Mitsumata for the banknote. After that, Mitsumata farming spread out all over Japan. In parallel, the material was started to use for various papers, especially calligraphy papers. It was called "Kairyo-shi" which means "Improved paper".
The fibre is shorter than Kozo's and longer then Gampi's. So, the paper has a characteristic just middle of the two materials. The colour is slightly darker and brownish than Kozo paper. Occasionally, It is used for the blended paper with Kozo, it becomes very strong paper.
At present, Mitsumata paper is not so popular, but the light brown color paper has quite a nostalgic atmosphere. It should be used more for various purposes.