Shoreline positions of southern Kashimanada coast facing Pacific Ocean have been observed with 4 X-band radars. The stretch is approximately 17 km long and extending from north to south with Kashima Port at the north and Tone River at the south. Half of the area is protected by coastal structures and the remaining is close to natural beach. Hourly-averaged radar images are processed to observe longshore distributions of shoreline positions and data collected for a year is discussed. The on- and off-shore migrations of shoreline positions are shown which are active for the protected areas and milder at un-protected areas. Waves were estimated with SWAN wave model and relationships between cross shore and longshore energy fluxes and observed changes in shoreline positions are discussed.