My company has a brunch in Vietnam and I stayed Danang office last month, for one week.
The purpose of this trip was to deepen the mutual understandings because one of the big problems is the lack of communication between the Vietnam team and the Japan team.

It was my first time to meet face to face with all members.
We've only had text communication so far.

During my stay, there were a lot of meetings and casual conversations. We often had lunch and dinner together.

To put it simply, the trip was tremendously great.
I got many lessons by working with them closely.

1. The reason "why they don't do" is not lack of ability but lack of understanding.

When in Japan, I often irritated about the output given by them because the content of the document/report was always lack of information.
Or, they sometimes delay the schedule without informing us in advance.

Whenever I experienced such a situation, I thought "You can't even do this!? What were you doing till now? Why you don't imagine our situation?" 
However, I've not feedbacked them at all.
I've made a blind assumption that they were lack of imagination so that they couldn't.

The first day of my trip, we held a meeting about reviewing our teamwork.
I pointed out your reports didn't have enough information. I explained in detail about the additional information we really need.
After that, the quality of their documents overwhelmingly improved.

I was really surprised and realized that the reason of lack of information is just they've never thought their information to us wasn't enough.

2. Breaking an invisible barrier

Before been to Vietnam, I've imagined the personality of each member and some of my impressions were negative such as bossy, dry, lazy and so on.

It turned out my impressions were wrong.
I found a dry impression is just his style, a lazy impression is mainly due to lack of English skill.
Ever members are very friendly, thoughtful, gentle people.

I was also told Vietnam members that they thought I got angry because my English is too fast and my voice tone is high.
And, the exclamation mark ("!") also let they suppose I'm angry.
I've never cared about the exclamation mark as ever. 

I've been feeling there was an invisible barrier between us during working in Japan, but now the barrier was broken.
It's nothing but a matter of English skill or talking attitude.

As the saying goes, Seeing is Believing.
I really learned this lesson from this trip.