Where is a fashionable city in your country?

Of course, I can say that the fashionable city in Korea is Seoul.

>>> CORRECT

I think the big reason is that Seoul is capital city.

>>> I think the big reason is that Seoul is the capital city.

It means that it is easier to affect trends from other countries than other cities. 

>>> CORRECT

Also, Most of eople who live in Seoul are rich to live. 

>>> Also, most of the people who live in Seoul are luxuriant.

Thue, They are interested in fashion and luxury goods and are sensitive about fashionable things. 

>>> Thus, they are interested in fashion and luxury goods and they are sensitive about fashionable things. 

Therefore, I belive that our capital city is more fashionable city.

>>> Therefore, I believe that our capital city is the most fashionable city.