Complex sentence: Excluding the Japan Railways Group companies, Tobu's 463.3 km rail system is the second longest in Japan after Kintetsu and covers large portions of Saitama Prefecture, Gunma Prefecture and Tochigi Prefecture, as well as northern Tokyo and western Chiba Prefecture.
Split into simpler sentences: Excluding the Japan Railways Group companies, Tobu's 463.3 km rail system is the second longest in Japan after Kintetsu. It serves large portions of Saitama Prefecture, Gunma Prefecture and Tochigi Prefecture, as well as northern Tokyo and western Chiba Prefecture.