1. After-five
アフターファイブ
After-five means after working hours. In many Japanese companies, working hours are until 5:00 pm. Bosses and co-workers often invite you out to eat outside of working hours. Some consider these to be important for communication and building relationships. By all means, please try to participate in socializing at after-five.

2. “Nomi-nication”
飲みにケーション
“Nomi-nication” is a word created by combining “drinking” and “communication.” Even people who keep a certain distance from each other at work can relax more than usual when drinking.

3. How to decline an invitation
誘いの断り
Bosses and coworkers sometimes invite you because they want to get to know you better. 1)When you decline, first thank them for the invitation.
2)Do not give specific reasons why you cannot participate. You can something like "I have something to do that day(その日は用事があって)" or "I have an appointment today(今日は約束があって)" and so on.
3)At the end say “Please invite me again later(また誘ってください)” or “Please allow me to participate in the next opportunity(次の機会には、ぜひ参加させてください)”, so that the person who invited you do not feel bad.

4. Socializing on holidays
祝日
Some companies hold sports events or company trips on holidays. In this case the schedule will be communicated in advance, so unless you have a special event, it is better to participate.
You may also receive a personal invitation on your day off. If you have something to do, there is no problem even if you politely decline. However, please decline politely.

5. Socializing outside the company
社外
Many people consider socializing with people outside the company to be part of their job, so if someone outside the company invites you to do so, you should participate as much as possible.
In addition, customers may be invited to high-class restaurants, or to play golf on their days off. The purpose is improving working relationships. Always pay attention to whether the customer is having fun.