It sounds nice and delicious but is definitely NOT authentic "Japanese" dish.
Soba (buckwheat noodle) is served with special tsuyu (sauce/soup) whose basic indredients are soy sauce, dashi (stock) from bonito, and sugar (or mirin).
There are many variations of soba dishes, some served hot, some served cold, with various toppings, but there won't be any
- ginger (some add wasabi to the tsuyu)
- sesame (some may sprinkle some sesame as garnish, though)
- lemon (something from the West)
- vinegar
- oil (except the oil from tempura...)
- cilantro (very exotic)
- cucumber
- tofu
The dressing of sesame oil, vinegar and ginger, and cucumber topping remind me of another dish called "hiyashi chuuka" cold Chinese noodle served with cucumber, ham, thinly fried egg, red pickled ginger, etc. But again it is not a Japanese dish, though very much common in Chinese restaurants in Japan.
