In Japan, natural disasters—such as earthquakes, tsunamis, volcanic eruptions, typhoons and floods—occur quite frequently. Although Japan’s land mass is very small, constituting only 0.25% of all land on earth, 10% of the world’s earthquakes occur in the country. For example, on January 17, 1995, the Hanshin-Awaji Earthquake struck Kobe and killed approximately 6,400 people. In 2011, more than 18,000 people were declared missing or deceased as a result of the Great East Japan Earthquake (GEJE) and the subsequent tsunami that hit the country’s northeastern coast. The powerful waves also damaged the nearby Fukushima Daiichi nuclear power plant in Fukushima prefecture, leading to reactor meltdowns and home evacuations for approximately 160,000 individuals. Recently, earthquakes in Kumamoto (2016) and Hokkaido (2018) as well as floods in western Japan (2018) killed hundreds of residents. These casualties illustrate that for the Japanese people, disasters are an unfortunate yet unavoidable part of their lives.
In the aftermath of disasters, the majority of the survivors are resilient. Nevertheless, a small proportion of them experience mental health disorders as post-disaster consequences. The Hanshin-Awaji Earthquake was a wake-up call for Japanese mental health professionals to understand the importance of post-disaster mental health (Kato, Asukai, Miyake, Minakawa, & Nishiyama, 1996). The GEJE was the next major disaster. In some affected regions, cities and their infrastructures were literally swept away. Survivors in Fukushima prefecture were overwhelmed by anxiety and uncertainty due to the unknown consequences of their exposure to radioactive materials. While no one died from the direct radiation exposure, the effects from other stressors (e.g., evacuation, family separation, community/job/school changes) have been significant (Hasegawa et al., 2015). Disaster survivors lost their trust in the Japanese authorities and electric power company, and the survivors have been stigmatized (Maeda & Oe, 2017).