The development of mathematics in Japan did not really start until the late 1600s. Mathematical treatises from China were the source of inspiration that kick-started further discoveries from Japan. As noted earlier, the Introduction to Mathematical Studies by Zhu Shijie, the great early-fourteenth-century Chinese mathematician, was eventually translated into Japanese and had a great influence in Japan.
“... the history of mathematics in Japan ... did not really begin until the end of the 16th century ...”(1)
(1) Joseph Needham, Science and Civilization in China, Volume 3 - Mathematics and the Sciences of the Heavens and the Earth, (Cambridge, 1959), p. 3.