Oyama Japanese Cuisine is a Japanese-style izakaya on the second floor of Sai Yeung Choi Street South in Mong Kok, Hong Kong, serving skewers and sashimi rice bowls. Its signature dish is A5 wagyu sushi with the surface seared, made to bring out the fat aroma of the thinly sliced beef. The dining room has wide spacing between seats and is decorated with wooden fittings and Japanese lanterns, and the afternoon set arrives about 15 minutes after ordering. On the A5 wagyu sushi, the rice is small relative to the size of the meat.