 Diesel railcars were introduced on the line from this date.At Kazusa-Nakano, the line connected with the Japanese Government Railways Kihara Line, which provided a route to the eastern shore of the Bōsō Peninsula and so plans to extend the line further to Kominato Town were subsequently abandoned.In 1942, the line was forced to merge with the Keisei Electric Railway, and remained a subsidiary of that company after the end of World War II.