Sushi Osa Ka is a Japanese restaurant near Hwarangdae Station Exit 3 that serves sushi along with udon and donkatsu. It also sells katsudon, kimchi nabe, and beef sushi. The owners traveled to Osaka in Japan, and the interior is decorated with figures as a nostalgic touch; reservations are needed when it is crowded. Apart from salmon, the sushi feels like frozen fish that has been thawed and is sometimes cold.