Yakisoba is Japanese stir fried noodles. It is served with Yakisoba sauce, similar to Tonkatsu or Okonomiyaki sauce.  Yakisoba is usually fried with sliced pork and vegetables like cabbage and bean sprouts.  It is a very popular casual food (or snack) everyone likes in Japan.  You can find Yakisoba at many places like Okonomiyaki restaurants, festivals, supermarket delis, and of course, home.