trip to Korea!

I traveled in Korea with my friend for 4days.
Until then I had never been to Korea.
At first,I was not so much interested in Korea and Korean culture,but now I think the that trip was so exciting that I want to know more about Korean culture and to go to Korea again.
I went to many places in Seoul,but the most (un)forgettable place was Dongdaemun because we got lost in Dongdaemun market at night when we looked for darkhanmari street.We can't understand the Korean language and the signbored (signboards) were not trancelated (translated) in Japanese,English or at least even Chinese at all,so we paniced (panicked).
After all, we could Eventually we arrived at darkhanmari restaurant,we learned an impotant(important) thing:"Unpreparedness is one's greatest enemy."
Another (un)forgettable thing is that Korean people was are much kinder and more warmharted than I thought.
At cosme shop in Myonggong (Myeongdong) ,when I spilled B.B cream on my jacket twice by accident, salesperson laughed,claped (patted) me on the back friendily and rubbed my jacket with make-up remover with utmost effort.I was happy for that behavior of  kind jesture from her because most Japanese salesperson's doesn't don't behave as that of Korea so I feel too formality impression.( I'm unsure of what you mean by " so I feel too formality impression") 
In Hongik, We found many grafitties graffiti on the at streets and they are our favorite.
Our way back to Tokyo,we listened to K-pop's BIGBANG.
(It is easy for me to be affected lol)

Forgettable means that you can forget it, unforgettable means you won't be able to forget it :). 

utrip to Korea!

I travelled in Korea with my friend for 4 days.
Until then, I had never been to Korea.

At first/Initially,I was not interested in Korea and/or Korean culture very much,but now I think that the trip was so exciting that I want to know more about Korean culture and to go to Korea again.

Initially , I was not too interested in Korea or its culture , but the trip was so interesting that it made me want to know more of its culture , and to have a desire to visit Korea again.

I went to many places in Seoul,but the most unforgettable place was Dongdaemun because we got lost in Dongdaemun market one night when we were looking for Darkhanmari Street.

We can't/don't understand Korean language and signboards are not translated in Japanese,English or at least in Chinese at all,so we panicked.

Finally, we managed to find  Darkhanmari Restaurant,and we learned an important thing/lesson:"Unpreparedness is one's greatest enemy."

Another unforgettable thing is that  Korean people are much kinder and more warmhearted than I thought/expected.
When I was at a cosmetic shop in Myonggong, I spilled B.B cream on my jacket twice by accident/accidentally, the salesperson just laughed,clapped me on the back in a friendly manner and cleaned my jacket with make-up remover with great/upmost effort ( cleaned my jacket with make-up remover diligently)

 I was happy/impressed by her behaviour because most Japanese salespersons do not behave like those in Korea . My impression is that Japanese salespersons are too formal/ not so attentive?

In Hongik, we found/saw many grafitties in the streets and they are our favourite.
Our way back to Tokyo,we listened to K-pop by BIGBANG.
(It is easy for me to be affected/touched lol)