The number of Japanese people who travel abroad has drastically decreased compared with that before the Covid-19 pandemic.

One of the reasons is that the Japanese Yen has dropped against other currencies.

In addition, the inflation rate in other countries is much higher than that in Japan.

I believe that Japan has become an affordable place from the foreign travelers' point of view.

or "from a foreign traveler's point of view"

Deflation in Japan had lasted for 15 years, so customers are used to the low price.

When the Bank of Japan set the target of inflation rate as 2% in 2013, most people doubted that the target willcould be achieved.

ThaIt is certainly achieved now, but the salary can not keep up with the rate.

Inflation hwas just caused by cheap Yen and the war in Ukraine.

The number of Japanese people who travel abroad has drastically decreased compared with thato before Covid-19 pandemic.

In addition, the inflation rate in other countries is much higher than that inof Japan.

I believe that Japan has become an affordable place from foreign travelers' point of view.

Deflation in Japan hads lasted for 15 years, so customers are used to low prices.

When the Bank of Japan set the target of inflation rate as 2% in 2013, most people doubted that the target willould be achieved.

ThaIt is certainly achievcomplished now, but the salaryies can not keep up with the rate.

Inflation has justbeen caused by the cheap Yen and the war in Ukraine.

The number of Japanese people who travel abroad has drastically decreased compared with that before Covidto before the COVID-19 pandemic.

One of the reasons is that the Japanese Yen has dropped against other currencies.

The worth of the Yen has decreased by 20% within the past 2 years.

In addition, the inflation rate in other countries is much higher than that inof Japan.

I believe that Japan has become an affordable place from the foreign travelers' point of view.

Deflation in Japan had lasted for 15 years, so customers are used to low prices.

When the Bank of Japan set the target of inflationary rate ast 2% in 2013, most people doubted that the target willould be achieved.

That is certainly achieved now, but theAlthough the 2% rate was achieved, the low salaryies can not keep up with the rate of inflation.

Inflation has just causworsened by ctheap undervalued Yen and the war in Ukraine.

The number of Japanese people who travel abroad has drastically decreased compared with thato before the Covid-19 pandemic.

article for "pandemic"
"compared to" is a set expression for this context

One of the reasons is that the Japanese Yen has dropped against other currencies.

article

The worthvalue of Yen has decreased by 20% within the past 2 years.

value is the common term for talking about prices and rates

In addition, the inflation rate in other countries is much higher than that in Japan.

I believe that Japan has become an affordable place from foreign travelers' points of view.

agreement plural

Deflation in Japan had lasted for 15 years, so customers are used to low prices.

need to be plural since there are many prices, not just one

When the Bank of Japan set the target of inflation rate ast 2% in 2013, most people doubted that the target willould be achieved.

article
"set as" does not seem right for this context
need to use "would be" since it's a hypothetical from the people's point of view

That is certainly the case now / That has been achieved now, but the salaryies can not keep up with the rate.

Need to be plural "salaries" because these are salaries of the country as a whole, not one single salary

Inflation hwas just caused by cheap Yen and war in Ukraine.

"was caused" meaning cheap Yen and war in ukraine caused it. "Has caused" means Inflation caused the cheap yen and the war.
Tip: if there is a "by" after the verb, it is "was/were" + verb

The number of Japanese people who travel abroad has drastically decreased compared with that before the Covid-19 pandemic.

Since "Covid-19 pandemic" is a thing, it needs an article, "the."

You could use just its name, "covid," without "the" and that'd be fine. You can also say "the pandemic" since there hasn't been a pandemic of a significant scale since.

One of the reasons is that Japanese Yen has dropped againstcompared with other currencies.

Deflation in Japan had lasted for 15 years, so custoonsumers are used to low price.

customers: People at a restaurant or store, place of business. It's generally more used to describe people at a specific place of business rather than people frequenting businesses in general, thus it rarely comes up when talking about economics.

Consumers: People who help money circulate throughout the economy by spending money on goods and services. This includes the business owners as well in the sense that they will also buy food, houses, and other life necessities.

When Bank of Japan set the target of inflation rate as 2% in 2013, most people doubted that the target willould be achieved.

"I doubt that will happen" in past tense is "I doubted that would happen." Since "doubt" is in past tense, "will" also has to be, otherwise you're claiming they were doubting that it would be achieved in the future from now.

That is certainly achieved now, but the salaryies can not keep up with the rates.

A "salary" is one person's pay, so to discuss all people's pay not keeping up with inflation, "salaries."

Inflation has just caused by cheap Yen and war in Ukraine.

Sorry, the meaning is unclear here.