Near-miss errors are errors that occur to a patient. However, the patient is never harmed because of fortuitous or appropriate intervention (Capucho, 2011;Kim, 2006). Although damage has not occurred yet, such errors are highly likely to cause a damage. Near-miss errors are also referred to as potential adverse events (Capucho, 2011).Near-miss errors are invisible. However, medical accidents are clearly visible. If near-miss errors are never addressed internally or debated publicly, it is nearly impossible to discuss contexts related to near-miss errors.Despite remarkable progress has been made for skill levels of medical staff and medical technology, there has not been significant progress in reducing the occurrence of medical accidents and subsequent damages (Asaoka et al., 2013;Kim et al., 2006). As it is difficult for patients to recover both physically and psychologically