<p>  Education regarding the environment incorporating studies that enable children to personally experience forests is an effective method of achieving environment-related education objectives in Japan. However, there are not many study examples that focus on educating children about the environment by giving them the opportunity to experience nature in a forest. Additionally, when studying about the environment, not enough attention has been devoted to transforming and sustaining children's awareness of the environment in the medium-to long-term. The objective of this research is to measure the transition of environmental awareness and to what level it is sustained by utilizing environmental education that subjects children to personally experiencing a forest in the medium-to long-term. The study focused on a year-long environmental education activity performed during an integrated studies course involving fifth-grade children. A 21-question awareness survey related to the objectives of environmental education and the integrated studies course was given several times in order to measure the level of awareness attained and retention of the information. The questionnaire was given before and after the activity, as well as one year after the activity as a follow-up. As a result, for one question regarding sensitivity to the natural environment, two questions regarding awareness of the natural environment, and two questions regarding overall comprehension, respondents displayed increased awareness after the activity when compared with the results taken before the activity. This increased awareness lasted for at least one year after the activity. However, for four questions regarding sensitivity to the natural environment, one question regarding awareness of the natural environment, and one question regarding overall comprehension, the increased awareness displayed by respondents disappeared one year after the activity based on the before-and-after survey results. Taking into account the results of the surveys, it is clear that some objectives of the environmental studies education utilizing a forest experience and integrated studies course were achieved and sustainable.</p>