Koyama spent a long time pursuing her calligraphic studies with Shosouin, an organization founded by Kuwahara Suiho, a master calligrapher of the Showa period, and became a freelancer in order to gradually develop her own creative activities.
In recent years, she has been creating a series of works that assemble letters and words by taking geometrical and architectural approaches. Koyama mainly uses ancient poems from places such as Man’yoshu, the oldest existing collection of Japanese poetry, and from the works of the Persian mystic poet Rumi to design images of her interpretation and she precisely places letters and words from those poems into her layouts. The process seems almost like using ancient remains as materials to build contemporary structures and this results in works that are both old and new at the same time.
Recently, Koyama has also created works of assemblage in which she stereoscopically collages different objects of which she has memories including personal cosmetics bottles and notebooks in previously used old boxes for plates and other articles. These are modernistic works filled with respect and affection for things that continue to exist without having being weeded out even after many years.