Although diverse water play has been expected to cultivate children’s sensibility, the serious accidents have been occurring around rivers. This study aimed to elucidate the regional social system that supports the safety of children’s diverse water play, and the issues for its sustainability were discussed, through a case study in Gujohachiman, Gifu prefecture. As a result, the safety was improved with three rescue functions around rivers. The functions were developed by five effects of seven approaches by various regional entities. It was the issue to strengthen the children’s approach to parents and to control the excess river use of tourists by regional government.