Shortly after you first arrive in Sotenbori in Like a Dragon Gaiden and start working for the Akame Network, you'll find a slightly troublesome request to locate some Okonomiyaki. The appropriately-named odd job, When will I taste Okonomiyaki?! is one of the first you can pick up in the streets of Shofukucho, but after scouring the region's restaurants, you're likely none-the-wiser as to where you find it.
Speaking of finding things; you can also collect Gold Balls and Locker Keys in Sotenbori, if you're looking for some special rewards. Either way, here's where to find Okonomiyaki for the odd job in Like a Dragon Gaiden.
Like a Dragon Gaiden Okonomiyaki location
You can find Okonomiyaki in Sotenbori, specifically at the Hiratai food stand on the Sotenbori Footpath at the south side of the river. Head down the stairs near either bridge and run along the south riverside until you're about halfway down to spot the shop built into the wall. It's pretty easy to miss this one, especially if you're running along the side of the footpath closer to the river.
Before this you probably spent a while running around Sotenbori Street looking in every restaurant for Okonomiyaki, but it's worth noting that none of the food-fetching odd jobs in the game involve restaurant food, which you only ever order for Kiryu. Instead, the food items you need will always come from Poppo convenience stores or either the Hiratai or Kukuru food stands for Okonomiyaki and Takoyaki respectively. These are marked with a shopping cart on the map instead of the restaurant knife and fork symbol.