The Amagasaki-ko Line had been a Mocho (cecum) line between Tsukaguchi and Amagasaki-ko since the direct operation in the direction of Osaka was started in 1898 by constructing a connecting line to Amagasaki Station on the Tokaido Main Line.
同線は1898年に東海道本線の尼崎駅への連絡線を設けて大阪方面との直通運転を始めてからは、塚口～尼崎港間の盲腸線となっていた。