Arakawa River Clean-aid began in 1994 with its activities to clean up the Arakawa River environment, which had been polluted during Japan’s period of high economic growth. It currently receives support from the national government as well as local governments bordering the river, and is mainly operated by citizen groups, with over 200,000 people having participated in its activities over the last 25 years. Implementation of the “Osaka Blue Ocean Vision,” adopted at the G20 Osaka Summit in June of 2019, will require promotion of further countermeasures to address river and marine debris.