Northern fur seals (Callorhinus ursinus, NFSs) are highly migratory otariid species that undertake a southward migration after the breeding season and overwinter in the pelagic waters of the North Pacific Ocean. Long-term pelagic observations revealed Japanese waters serve as one of the primary wintering grounds that provides sufficient and predictable food for NFSs. As opportunistic predators, NFSs diets are highly diverse and their distribution as well as at-sea behaviours are closely link to the distribution and availability of prey species. On Japanese wintering grounds, NFSs tended to aggregated along specific topographic like continental shelf and breaks, and in highly productive water regions like the Kuroshio-Oyashio transition Zone. Previous mark-recapture data further uncovered the intermixed stocks overwintering in Japanese waters are primarily from islands in the Sea of Okhotsk and the Bering Sea. Historical data outlined NFSs’ distribution pattern, feeding habits, and linkage to environmental conditions. However, these snapshot records only provided partial information and unable to determine the environmental mechanisms that influence migratory strategies and foraging ecology due to spatial and temporal limitations. In this study, we combined biotelemetry technology with stable isotopic information to provided new insights into the habitat preference and regional foraging strategies of NFSs during non-breeding season. We deployed satellite tag on five male NFSs captured in the Sea of Japan to collect their northward movement data and measured stable isotopic ratio along four individuals’ whiskers to provide foraging records. Tracking data demonstrated four individuals’ destination regions, individual variability in migration pathways, and influence of oceanographic features on their at-sea behaviours. Foraging-related behaviours highly occurred along continental shelf and shelf break regions, likely due to the prey-rich waters created by distinctive topographic features. NFSs preferred feeding within specific water temperature ranges, possibly influenced by productive water masses that can aggregate abundant food resources. Oscillations along the length of the whiskers were observed both in carbon and nitrogen isotopic values. Nitrogen isotopic values in whisker roots were found to vary among individuals. Average stable isotopic ratio of individuals tracked to the Pribilof Islands was the highest (δ¹³C = -16.93±0.32, δ¹⁵N = 15.82±1.49), and isotopic values of individuals with smaller body size were lower. Isotopic compositions likely reflect the difference in diet selection and habitat preferences. Combining tracking data with isotopic compositions, we estimated NFSs dietary information and strengthen the understanding of oceanographic features that possibly aid in foraging of NFSs on the wintering grounds of Japan.