The second part of the SDGs (Sustainable Development Goals) series is "Let's protect the richness of the ocean." In Japan surrounded by the sea, we have received its blessings since ancient times and lived with the sea. What are the challenges and secrets that such Japanese people should work on to protect the richness of the sea? What are the efforts to protect the richness of Japan's sea, such as junior high and high school students who fight to reduce the "marine garbage" that is the cause of marine pollution from the root, and the development of environmentally friendly wave-dissipation blocks? I'm going to find the way for Japan to go.