Although the Seto Inland Sea is very enclosed, phenomena in the Pacific Ocean should strongly influence the marine environment in the boundary regions (such as the Kii and Bungo Channels). A typical example of such influences is a kyucho (in Japanese) in the Bungo Channel. A kyucho is a sudden stormy current that is usually accompanied by a rise of water temperature and has been studied intensively since the mid 1980s. Kyucho have been observed in many bays along the Japanese coast that face the open ocean, for example Sagami Bay (Matsuyama and Iwata, 1977), Uragami Bay (Tanaka et al., 1992) and Wakasa Bay (Yamagata et al., 1984).