This chapter summarizes recent advances in understanding the nutrient supply processes to the shelf and slope region facing the Kuroshio off southern Japan in terms of the combined effects of mesoscale and submesoscale ocean variations, with a particular focus on numerical modeling. In addition to the Kuroshio path variations, the key factors to control the nutrient supply are frontal disturbances that are generated primarily when the Kuroshio or the northern Kuroshio front comes into contact with the coastline or with shallow bottom topography on the shelf with a narrow width (<40 km). The frontal disturbances contribute to both vertical and horizontal advection of nutrients to the shelf and slope region, propagating eastward along the Kuroshio path and sometimes developing from submesoscale to mesoscale. In contrast, the Kuroshio-induced upwelling in the shelf and slope region can propagate westward as baroclinic coastal-trapped waves along the coast. As a result, the Kuroshio-induced nutrient supply in the shelf–slope region off southern Japan can be controlled by both eastward- and westward-propagating disturbances.