Gamtansungshin Sushi is a Japanese restaurant in Gangnam, Seoul, serving futomaki, sakedon, and soba. It offers large futomaki, maze soba, and eel rice bowls, and the food tends to be presented attractively. Food comes out quickly, and a wait is required on weekend evenings; the building's restroom is clean. Portions are generally small, salmon and uni toppings are thin or sparse, and staff service is brusque.