The trains started running from April 2013, their name is "Akamatsu(あかまつ)" for red one and "Aomatsu(あおまつ)" for blue one.
If you would like to try "Akamatsu", you need to pay (540yen/person) extra. This price include one drink(can choose from tea, coffee, apple juice and orange juice).
Taking "Aomatsu" is without any extra charge than ordinal fare.
I personally recommend Miyamai・Miyatoyo line which train runs by the sea in some part. Although in autumn season, Miyafuku line can offer beautiful coloured mountain view.
On the trains only Japanese style toilet available.
For timetables, please check on hyperdia. http://www.hyperdia.com/en/