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Beach profile evolution under storm sequence forcing presents an emerging research topic that has only been investigated at a limited number of sites. The occurrence and effects of storm sequencing on beach profile evolution are studied at Hasaki Beach, Japan, using weekly beach profile and two-hourly offshore wave measurements. During the 25-year study period, the supratidal beach at Hasaki is subjected to long-term accretion and steepening while the shoreline shows a long-term oscillation. In addition, oscillations of the supratidal beach volume and the shoreline at semi-annual and annual intervals are identified, which are largely controlled by the variability of the wave height. Hasaki Beach is subjected to frequent storms that often cluster in sequences, especially during the extra-tropical cyclone season (January to March). The majority of storms and sequences generate erosion of the beach above the low water level but some also lead to recovery. Despite a tendency for storms and storm sequences with larger power to cause more erosion, the present data does not demonstrate increased beach erosion by storm sequences. Following these findings, the tendency of the beach to evolve towards equilibrium and the importance of the antecedent beach morphology are demonstrated. • Accretion and steepening of the supratidal beach at Hasaki during the 25-year study period. • Annual and semi-annual oscillations of the shoreline, supratidal and intertidal beach volume are controlled by the wave energy. • Storms and storm sequences are quantitatively defined for Hasaki Beach and the definitions are discussed. • No indication for increased erosive effect due to storm sequences compared to individual storms of equivalent power • The antecedent beach morphology and the evolution of the beach towards equilibrium are found to be important. [ABSTRACT FROM AUTHOR]