Why study an art, especially a foreign art? Answer because it is transformative. Art can challenge us and bring us to precipices in our mental, emotional and spiritual selves which take us over the edge of our boundaries.
I remember many years ago reading the story of the Japanese warriors who were also required by their standing in society to learn cultural studies such as Ikebana flower arrangement, Tea Ceremony or Cha do, calligraphy or Shodo as well as Aie do swordsmanship. At the time I thought, why? That seems weird soldiers doing flower study or reading poetry.
In sumie and Zen arts as we progress we must study the world around us and this is tranformative and affects our art. It is not just enough to learn a technique and do it, although that is necessary. To be more than average one must cultivate the spirit and mind with everything available, poetry, philosophy, art, music, song, politics, architecture, history etc....
Here is a great link to Japanese culture from PBS in America where there are links to all things Japanese cultural.
Go to; http://www.pbs.org/empires/japan/resources_3.html