The Korea/Tsushima, Tsugaru, Soya, and Tatar Straits connect the Japan/East Sea (JES) with adjacent seas. Of the four straits, the Korea/Tsushima Strait (KTS) provides the vast majority of inflow into the JES and plays a major role in determining its dynamics. The heat and salt balances within the JES are in large part determined by the inflow through the KTS. Understanding of the relationships and forcing mechanisms of the inflow from the Yellow and East China Seas through the KTS is important for understanding the circulation of the JES. Ultimately, flow through these Asian seas plays an important role in determining the temperature and salinity characteristics of North Pacific circulation.