Japan has no culture of tipping.
Contrary to the US, you don’t need to pay money more than just required.
But, there are few occasions that you can tip to workers.
In Japanese style hotels called Ryokan or hospital, you might need to pay money to express gratitude to the staffs work there.
This is more formal than tipping. You usually put the money into the envelope.
However, they don’t necessary take it because it is weird for getting the extra money in Japanese culture.
So, it actually depends on the situation.
But, you won’t have any trouble for not tipping workers there at all.
Another example hotel has a system a lot bigger than tipping.
Somebody claims it is kind of bribery, but some people buy expensive things like wines or gift certificates or even cash over $100 after the patients’ illnesses are cured.
Although the culture in Ryokan is getting less popular every year, the gratuity for doctors still exists.
Anyway, you should pay too much attention to tipping.
It’s good that you don’t need to pay the extra because you can save your money.
Also, tipping in ryokan or hospitals is not mandatory.
So, it could be a better option not to pay any extras after all.