Lemons in Tokyo?

I am travelling to Tokyo in March next year and I happen to love lemons. I eat lemon with all foods like ramen, udon, miso, sushi, shrimp, fish, and even doritos. I am barely able to eat any of these foods with lemon. Do restaurants in Tokyo normally carry lemons? If so, are they expensive? Can you buy lemons/lemon juice at local grocery stores and/or gas stations?

Some restaurants may have lemons on hand, but it may be best if you carry a small bottle of lemon juice with you. It should be easy to find at any grocery store, convenience store, 100 yen store, etc. It is not expensive.

Most restaurants and bars carry lemons for purposes like yours, and they are for free. Just ask for "lemon."

But for example, places that only serve food commonly eaten without lemons may not carry them. Ramen bars is a typical example.

In other words, places that don't carry lemons serve food and beverages that are designed to go well without lemons. Hence, the chef might not appreciate it if you use your own lemon on it.

In any case, it's not really polite or sometimes even prohibited to bring in your own food, drinks or seasonings into restaurants/cafes/bars and use them. If you do, do it discreetly.

You might want to research japanese foods that are served with lenon before you go. Chicken karaage comes to mind.

Yes, what Uco said. For example if you can't eat sushi without lemon, it's not really acceptable to bring your own lemon into a sushi restaurant and start squeezing.

If it's that much of an issue, then maybe you should buy take-out food from department stores and eat it in your hotel room, adding lemon juice to your heart's content.

In the drink menu and tea in the many restaurants and cafes in Japan.
If you are made ​​to choose the lemon tea and milk tea, if you choose the lemon tea, black tea comes with a slice of lemon most.

That being said, if you do want to go out I would try izakaya that have larger menus. They will likely have lemon to serve with certain dishes, so you could probably ask for some at the beginning of your meal.

I think bringing the lemon juice is your best option. Certainly you don't want to be seen squeezing your own lemon at a table but if you put a few droplets into your food from the little juice containers, I don't think anyone will care. At worst they'll just think you're strange.

I can assure you that if you try to do that in a nice sushi restaurant, they certainly will care.