Short answers, pulled from the story.
The Sea of Japan is bordered by Japan to the east and south, the Korean Peninsula to the west, Russia to the north, and Sakhalin Island to the north-east. The Japanese islands of Hokkaido, Honshu, and Kyushu form the eastern and southern boundary.
South Korea contends that the name East Sea was historically used before Japanese colonial rule and officially requests that it appear alongside Sea of Japan on maps and in international documents. North Korea advocates for the name East Sea of Korea. Japan argues that Sea of Japan has been the internationally accepted English term since the early 19th century.
The Sea of Japan reaches a maximum depth of 4,568 metres. Its mean depth is 1,752 metres, and the deepest part is the Japan Basin in the north, which is of oceanic origin.
The Sea of Japan has high dissolved oxygen because cold winter air drives surface convection in the northern part of the sea, pushing oxygenated water downward. Oxygen concentration reaches 95 percent of saturation near the surface and about 70 percent at 3,000 metres, supporting rich aquatic life of more than 3,500 animal species.
The International Hydrographic Organization's document S-23, which has used the name Japan Sea since its first publication in 1928, has not been updated since 1953. In 2020, the IHO decided to develop a new digital standard, S-130, which will assign unique numerical identifiers to maritime areas rather than names, sidestepping the dispute rather than resolving it.
The Sea of Japan supports more than 800 species of aquatic plants and more than 3,500 animal species, including about 1,000 species of fish, more than 900 species of crustaceans, and 26 species of mammals. Key commercial fish include herring, sardines, bluefin tuna, squid, and salmon; seals and whales represent the sea mammals.