The first submarine telegraph cable was laid in the fifth year of the Meiji Period (1872) across the Kanmon Straits. For long distance telephone, an eight-core doube-shielded shallow sea cable was also laid across the Kanmon Straits. Later, around 1937 when the "Manchurian Incident" occurred, a submarine cable for conveyance was laid as part of a Japan-Manchuria route across the Korean Straits. A coaxial submarine cable was laid for the first time in the fortieth year of the Showa Period (1965) across the Bisan Straits in the Inland Sea of Japan.

---