When you come to Kagawa, particularly in the city of Takamatsu, you will see some very nice and quaint old-style trains rumbling around. This is the Kotoden Train company. The owner, Mr. Manabe, is a very nice man and I have had the chance to meet him several times. The trains are, in many ways, a symbol of the city so when you come here it would be helpful to know where they go.
Here is a PDF file with the maps of the three train lines. http://www.kotoden.co.jp/publichtm/kotoden/eg/img/english.pdf
Before you come here make sure to print this off and keep it in your pocket. There is great tourist information all over this guide, and also information about where to find the best udon restaurants around.
The trains are easy to access. The staff and conductors are really kind and helpful. This is a terrific way to see how the locals get around, and you can have a unique commuting experience when you ride the Kotoden trains.