"In Japan, “Shinrin-yoku”, which can be defined as “taking in the forest atmosphere or forest bathing” is currently receiving increasing attention for its capacity to provide relaxation and reduce stress. Humans empirically recognize that getting in touch with nature provides a feeling of comfort. In carrying out their investigations on “Shinrin-yoku”, the authors of this article have assumed that the reason underlying this feeling of comfort with “nature” or “natural matters” is closely linked with the human evolutionary process. Frumkin supports this view and reports that a deep-seated connection between the natural world and humans is unsurprising from an evolutionary perspective; based on this description, we have also assumed that human physiological functions have had to adapt to the natural environment through the course of evolution. Consequently, living in our modern “artificial” society is inherently stressful. Given this background, it should be natural for humans to feel a sense of comfort or affinity with the natural environment. “Shinrin-yoku” is considered to be one of the most accessible ways to get in touch with the natural world and to lower excessive stress to levels that are commensurate with what our bodies are “expected” to cope with. In Western societies, this approach has been incorporated into the lives of individuals since the nineteenth century. The best known example of this may be Kneipp therapy in Germany. Kneipp therapy utilizes forests mainly as the fields for exercise therapy, which is one of the five pillars of the method. However, although Kneipp therapy somewhat realizes the concept of “Shinrin-yoku” in a practical context, its precedents in the Western countries are based mostly on empirical knowledge. The effects of “Shinrin-yoku” have yet to be verified by scientific evidence. The term “Shinrin-yoku” and its concept were introduced in Japan by the Forest Agency of the Japanese government in 1982. Over the 25 years that have passed since then, interest in stress control or relaxation among those living in our modern-day society has greatly increased. In addition, in the fields of medicine and nursing, there has been a trend toward evidence-based medicine or nursing, emphasizing the need for scientific evidence. Based on this social background, in 2005, the Forest Agency instituted the “Therapeutic Effects of Forests Plan,” which emphasizes the importance of scientific investigation."