1.Colleagues help each other
助け合う
If you have good relationships with your co-workers, they will surely help you when you are in trouble. However, don't just ask for help all the time, give help when your colleague is in trouble too. Your division or responsibility may be different, but do not be afraid to ask “Can I help you?”.

2. What to say when talking with colleagues
同僚と話す
Japanese has a variety of ways of speaking, such as polite and casual, depending on the person and the situation. When meeting someone for the first time, we speak politely, but when we get to know a person, we speak more casually. If we don't speak casually, our friend may feel that it is difficult to get close to us.
On the other hand, you may speak with a new employee in a casual way during breaks. However, when you are at work, try to speak like a professional, not like a friend. Speak in a way that is appropriate for the workplace. Especially be careful in front of customers.

3.Do not mix public and private
私と公
In some companies, there are couples who get married within the company and continue working at the same workplace. If these people are speaking and acting politely to each other, they clearly separate "work" and "private". So if they have a fight outside of work, they should not bring the fight into the workplace. The same happens when something sad happens in private life. A member of society is someone who can switch between "public" and "private".

4. Borrowing and Lending
お金を借りる
In Japan, it is not common to borrow or lend money even to close friends. So people may be a little surprised if you say, "Please lend me some money." Moreover, the Japanese like to split the bill. You may think, “Japanese people are stingy”. However, this is not the feeling of not wanting to pay more than others, but the feeling of not wanting to owe money. Of course, if you forget your wallet when you go out to eat, you can borrow money. However, it is important to return it immediately, no matter how small the amount was. Also, when borrowing umbrellas and other items, don’t forget to return them. Those who do not return what they borrow lose credibility and trust.

5. Courtesy even in close friendships
親しき仲にも礼儀あり
No matter how hard you try to get to know someone, you still have to follow the minimum manners. You should never do something that makes the other person feel embarrassed or uncomfortable, even if you are close to them. In order not to destroy the good relationship that you have worked so hard to build, remember the saying, “Even close relationships have courtesy.”