Wei Xu is a Master’s student at the School of Oceanography at Tokai University, Japan under Professor Yinji Li’s supervision. He completed his undergraduate studies at the same university. He has been interested in Japanese small-scale tuna fisheries and conducting relevant research in Iki Island, Nagasaki Prefecture. Around Iki Island, there are bluefin tuna spawning grounds, and in the past, pole-and-line tuna fisheries were flourishing in the area. However, in recent years, due to the increase in large-scale tuna fishing at spawning grounds during the spawning season, the catch of pole-and-line fishing has decreased. The pole and line Bluefin tuna fishing in the Iki area has also been seriously affected, which caused the survival of the pole and line tuna fishers very challenging. Under such circumstances, his Master’s research will continue to focus on the small-scale tuna fisheries in Japan and analyze the current situation from the perspective of Blue Justice, taking Iki Island, Nagasaki Prefecture as a case study.