Happy Cheese Smile Haeundae is a fast-food restaurant in Haeundae Haeridan-gil that serves donkatsu, tteokbokki, and sweet potato fries. The cream tteokbokki is mildly spicy, and adding cheese brings a charred flavor while the donkatsu breading stays thin. Staff who understand and speak English and vegetarian options make ordering easier for foreign and vegetarian customers. The shrimp fries and sirloin donkatsu are the disappointing menu items.