There are three active left-lateral strike-slip faults in the coastal area around Obama Bay, Fukui Prefecture. They are the Kumagawa fault, the FO-A and the FO-B faults. The latter two are submarine active faults. The marine terrace surfaces in this area are classified into H and M surfaces in descending order. The M surface is correlated with that formed in MIS 5e. The height of the former shoreline of the M surface, ranging 10 m to 24 m, is a planar structural marker that records the actual crustal movement. The Kumagawa fault and the marine active faults may not appear to be continuous. However, the calculated crustal deformation based on such fault model is completely inconsistent with the structural contours defined by the former shoreline. The tectono-geomorphic features strongly suggest that three active faults constitute continuous one fault system.