http://jorudan.co.jp/自己一段一段计算是自由行的基本功之一呀！
日本东京都至长野县北佐久郡轻井泽町 - Google地图
http://www.google.cn/maps/dir/%E6%97%A5%E6%9C%AC%E4%B8%9C%E4%BA%AC%E9%83%BD/%E6%97%A5%E6%9C%AC%E9%95%BF%E9%87%8E%E5%8E%BF%E5%8C%97%E4%BD%90%E4%B9%85%E9%83%A1%E8%BD%BB%E4%BA%95%E6%B3%BD%E7%94%BA/@36.0353982,138.8910422,10z/data=!3m1!4b1!4m14!4m13!1m5!1m1!1s0x605d1b87f02e57e7:0x2e01618b22571b89!2m2!1d139.6917064!2d35.6894875!1m5!1m1!1s0x601dd23c3fc1a393:0x99118f4883da71f9!2m2!1d138.596955!2d36.3482902!3e3
长野县北佐久郡轻井泽町至日本长野县松本市 - Google地图
http://www.google.cn/maps/dir/%E6%97%A5%E6%9C%AC%E9%95%BF%E9%87%8E%E5%8E%BF%E5%8C%97%E4%BD%90%E4%B9%85%E9%83%A1%E8%BD%BB%E4%BA%95%E6%B3%BD%E7%94%BA/%E6%97%A5%E6%9C%AC%E9%95%BF%E9%87%8E%E5%8E%BF%E6%9D%BE%E6%9C%AC%E5%B8%82/@36.4368942,138.1309083,11z/data=!3m1!4b1!4m14!4m13!1m5!1m1!1s0x601dd23c3fc1a393:0x99118f4883da71f9!2m2!1d138.596955!2d36.3482902!1m5!1m1!1s0x601d1400e84368c7:0xcb8d6d363210cddd!2m2!1d137.9720341!2d36.2380381!3e3
日本长野县松本市至Kusatsu Hot Spring - Google地图
http://www.google.cn/maps/dir/%E6%97%A5%E6%9C%AC%E9%95%BF%E9%87%8E%E5%8E%BF%E6%9D%BE%E6%9C%AC%E5%B8%82/Kusatsu+Hot+Spring,+Kusatsu,+Agatsuma+District,+Gunma+Prefecture+377-1711%E6%97%A5%E6%9C%AC/@36.4368964,138.1916402,10z/data=!3m1!4b1!4m14!4m13!1m5!1m1!1s0x601d1400e84368c7:0xcb8d6d363210cddd!2m2!1d137.9720341!2d36.2380381!1m5!1m1!1s0x601de6537acdb233:0x12ef9439de3e2003!2m2!1d138.593274!2d36.621758!3e3

你这个路线安排的就有问题，所以时间会那么长。
先从新宿站坐JR的特急列车去松本，有直达列车；然后从松本坐车到长野，转新干线到轻井泽，然后从轻井泽巴士去草津，最后从草津坐巴士转JR回东京。

你下个乘换案内app就明白了