The Arakawa River, a Class 1 River, has a natural levee. From the mouth of the river for 20km the waters are brackish, making the area rich in both sea and freshwater biodiversity. Every year, the Arakawa Clean Aid Forum organizes refuse clean-up activities for 10,000 participants at 100 locations in the same area, and conducts research and analysis of the refuse. However, we also recognize that periodic conservation activities are also necessary in order to protect the endangered species living along the Arakawa River. Through these activities, we will introduce an "adopt" system (as in "adopt a child") whereby the public and businesses periodically manage natural areas at appropriate locations along the river basin. In the first year of the system's introduction, the authorities, river basin authorities, and the tens of companies will meet for discussions to establish policies for a system that ensures the continued protection of endangered species through collaboration between NPOs and businesses. From the second year onwards, we will refine the number of participating businesses, draw up a year-long implementation plan, conduct a trial of the program, and assess its practicality, with the aim of full implementation to establish a program. In doing so, we will create an "adopt" system in the area of river management for the protection of endangered species formed by businesses and NPOs, with the potential for the system to be expanded and implemented in other river regions in future.