This dataset contains shoreline positions extracted from repeated cross-shore elevation surveys conducted at Hasaki Oceanographical Research Station (HORS), Ibaraki Prefecture, Japan (35.842°N, 140.763°E). The surveys were carried out by the Port and Airport Research Institute (PARI) by using leveling. Temporal coverage: 1987-08-28 to 2026-01-27 (433 surveys)Spatial coverage: 11 alongshore transects at 40 m intervals, spanning 400 m (from -200 m to +200 m relative to the pier) Column description: - date : Survey date (YYYY-MM-DD) - -200 to 200: Shoreline position (m) at each alongshore transect, where the column header indicates the alongshore distance (m) from the pier. Negative values are toward Choshi; positive values are toward Kashima. Shoreline position is defined as the cross-shore location where the beach elevation equals 1.4 m above the Tokyo Peil (T.P.) datum, determined by linear interpolation between adjacent survey points. Cross-shore positions are measured relative to the pier baseline (0 m), with positive values directed seaward and negative values directed landward. Each transect consists of elevation measurements at 5 m cross-shore intervals from -115 m (landward) to +100 m (seaward). Missing values (empty cells) indicate surveys where a valid 1.4 m contour crossing could not be determined for that transect, typically due to insufficient data coverage. The overall data completeness is 99.1%. Units: meters (m)