My last shooting on that day was Kiha 201 Series "Niseko Liner" rapid train.
Kiha 201 Series debuted in 1997 and designed at the same time as 731 Series. The carriages have the almost same body and specification as 731 Series and can couple with each other. Besides, the carriages equip the active pneumatic tilting on curves to run on the unelectrified section at an as fast speed as the electric carriages.
Kiha 201 Series is mainly in service as rapid or local train on Hakodate Main Line going through the electrified section and unelectrified section farther than Otaru Station. The sets used to be in Sassho Line between Sapporo Station and Hokkaido-iryodaigaku [Health Sciences University of Hokkaido] Station before the electrification in 2012.
Though no more than four 3-carriage sets exist, Kiha 201 Series plays an important role in connecting Sapporo Urban Area and the unelectrified section, where the train carries a certain number of passengers, with its specification. From my point of view, Kiha 201 Series is a very interesting carriage because of its tilting, which is rare to be equipped to a commuter train, acceleration performance, and availableness to couple with 731 Series.