If you have ever been to Tokyo, I am sure you have seen all of the soba restaurants inside the train stations. They are typically full of businessmen on their way to work who want to get a quick bite to eat, but they are actually so good.
The most popular chain that I know of is called Soba Ichi, and it is actually really good. It is one of the best deals you will find in all of Japan, as the soba they serve typically ranges from $3-5. My personal favorite is the cold soba with an egg and kakiage (which is a type of tempura). I forget exactly how much this dish costs, but I think it is around $5 or so. However, they have a bunch of different toppings and options, so you can get almost any type of soba you like!
I also read an article that there is a Soba Ichi location at Higashi Koganei Station, and this one is special because it uses a robotic arm to make the soba dishes (there are no humans, to cut down on costs). While I have never personally been to this location myself, it sounds super cool, and I would love to try it out on my next trip to Japan. Eating at Soba Ichi is already super quick because you pay outside at a machine (and get a ticket, which you typically hand to the chef), but this would expedite the process even more if there is a robot making the soba.
If you are ever craving a snack in Tokyo, just go to the nearest train station and find a Soba Ichi!
Soba Ichi Recommendation Rating: 3.5
1: Something worth checking out if you have time
2: Something that is a hit for some people, but not a must for everyone
3: Something worth prioritizing if interested
4: Something worth making time to check out
5: An absolute home run, worth going out of your way for