1 December 1988: Second stage opened between Shin-Kiba and Minami-Funabashi, and between Ichikawashiohama and Nishi-Funabashi.
1 Desember 1988: Tahap kedua dibuka antara Shin-Kiba dan Minami-Funabashi, dan antara Ichikawashiohama dan Nishi-Funabashi.