This study conducted a field survey and multiproxy analyses on sediment cores retrieved from the Kobatake-ike pond in Choshi City, Chiba prefecture, Japan. Kobatake-ike pond is located at a high elevation (i.e., 11 m above present-day sea level) and faces the southern part of the Japan Trench. Three sedimentological events were detected within the continuous mud and peat sequences of three thousand years. Based on the multi-proxy analyses, including mineralogical composition, diatom assemblages, and geochemical markers, these sedimentological events were associated with past tsunamis. The most recent event was a sandy layer from the AD 1677 Enpo tsunami, reported by an earlier study conducted in the pond. The estimated recurrence interval for tsunamis was approximately 700 years, comparable to that of the central part of the Japan Trench. The timing of at least two of three sedimentological events seems to have been close (i.e., intervals of few tens of years) before or after the occurrence of large earthquakes and tsunamis along the central part of the Japan Trench. This implies a possible spatiotemporal relation of earthquake generations between the central and southern parts of the Japan Trench, which can be associated with drastic changes in stress fields in the neighborhood of the rupture area. The risk of future large earthquakes and tsunamis along the southern part of the Japan Trench seems exceptionally high, considering the stress change caused by Tohoku-oki earthquake with 9.0 Mw in 2011. This study necessitates the need to investigate the spatiotemporal relationship of large earthquakes from the perspectives of geology, seismology, and history.