Nikuman -is a Japanese food made from flour dough, and filled with cooked ground pork or other ingredients. Nikuman are steamed and often sold as street food. From about August or September, through the winter months until roughly the beginning of April, Chūka man are available at convenience stores, where they are kept hot.
Often described as a “Japanese pizza”, okonomiyaki is actually more like a pancake. I think the reason people compare it to a pizza is because you can fill it with just about anything that suits your fancy. Fitting, given that its name literally translates to “grilled as you like it”. http://www.pbs.org/food/fresh-tastes/okonomiyaki-classic-japanese-street-food