Rare-earth elements and yttrium (REY)-rich mud is a next-generation, clean, new resource. A vast amount of REY-rich mud lies under the deep-sea floor in Japan’s exclusive economic zone around Minamitorishima Island. The Ocean Resources Research Center for Next Generation (ORCeNG) at Chiba Institute of Technology is pursuing cutting-edge research into practical development of this new resource. We have used REY-rich mud from the seafloor around Minamitorishima Island to fabricate a white LED, which is the first in the world to employ rare-earth elements refined from seafloor mineral resources. This iconic achievement, showing the way toward a society that will live in harmony with the environment, is the light from Minamitorishima.