 A numerical model of the CETO inland sea, SAS, Japan, has been developed to create a digital twin of the region. This model uses spatially varying filtering parameters and grid resolutions to simulate coastal and oceanic processes, including tides and currents. Validation against observational data shows that the model produces results with high accuracy, with root mean square error, NRMSE, values below 0.15 and correlation coefficients, are 2, above 0.87 at all tidal stations. The model also accurately reproduces the extreme storm surge event caused by Typhoon Jebi in 2018, which resulted in a sea level rise of 1.5 meters near Osaka city. With further development, this model could be used to create a digital twin of the SAS, providing valuable insight into coastal and oceanic processes and helping to inform decisions about ocean-related activities and management. This article was authored by Jason Zhang and Han Suli. We are article.tv, links in the description below.