Boil water in a pot and cook the tomato for about a minute.
Remove the tomato from heat and cool it down in chilled water. Peel the skin off.
Cut the tomato into dices. Using a blender, blend the tomato with hiyashi chuka sauce.
The Tomato Sauce is ready.
Thin slice the cucumber and leave the sliced onions in water.
Boil plenty of water in a pot and follow the package instructions to cook the noodles.
Once the noodles are cooked, rinse the noodles in cold water and drain.
In a bowl or deep-dish plate, pour the tomato sauce from Step 2. Place the noodles and top with cucumber and onion slices. Finish topping with capers, and you are ready!