They advise taking more time for oneself, keeping a sense of humor, and keeping in touch with friends back in Japan. Beyond this, however, there are some psychological patterns of learning that account for some of the mood swings. Learning to do something differently, like so many tasks in our daily lives in Japan required, isn't too difficult on the brain. However, from a behavioral standpoint, re-learning something, again, upon return to one's home country, places a great deal of stress on the brain. Relying on friends is fundamental in getting through the repatriation process.
Friends can make life less difficult.
They talk to you. They help you find jobs. They can be roommates when you realize that the board of education is not paying for half of your housing costs anymore. However, even the best of friends can be a challenge to you at times. You are not the same person as you were when you left Japan, but neither are your friends who weren't with you in Japan.