Introduction Managers often face tough situations that require them to make decisions under uncertainty. Examples of factors that determine the effectiveness of decisions in such situations include personality, values, psychology, and sociological influences. Personality refers to a person’s dynamic psychological dispositions that determine how they relate and adjust to their environment as well as to the people around them. It is determined by heredity, environment, and aging. On the other hand, values refer to ideals that people use to decide whether behaviours or actions are right or wrong. They are divided into two groups namely cultural and personal values. Values determine people’s behaviours and their reactions to different circumstances. They also play a key role in influencing decisions. Psychology affects decision making in three main ways namely perception, attribution, and framing. Higashi is the director of the JET program and Kelly’s supervisor as well as the other ALTs. He has made several decisions that are highly flawed and that provide lessons on how managers manage during moments of uncertainty. These decisions will be analysed from two main perspectives namely personality and value based as well as psychological. The decisions that will be analysed include denying Kelly sick leave, concluding that foreigners feign sickness in order to increase their weekend days, giving erroneous information to Kelly and her colleagues, and pushing Kelly to participate in activities that are considered feminist in Japan. Case study analysis Prospect theory is a behavioural model that people use to make decisions that involves prioritising the value of loses and gains over the final outcome of the decision made (Vis, 2011). This theory can be used to analyse Mr. Higashi’s decision to deny Kelly and the other ALTs sick leave and instead replace it with paid leave. He is not interested in the final outcome of the decision but the losses and gains involved. Higashi is less willing to embrace the gains that will come from giving Kelly and the ALTs sick leave. Instead, he considers the losses that the program will suffer if he gives Kelly sick leave. Therefore, he replaces sick leave with paid leave. The decision is made after an evaluation that is set by social comparison. One of the three principles of prospect theory is loss aversion (Vis, 2011). In this case, the losses loomed larger than gains because in Japan, workers are highly committed to their jobs, work on Saturdays, and utilize their leave well. Higashi is worried that Kelly’s work ethic is not fit for the program because native employees work even on Saturdays. The ALTs lack of commitment was unacceptable to Higashi. In order to mitigate the losses, he replaced sick leave with paid leave. He is not convinced that Kelly and her colleagues could all be sick and absent from work simultaneously. In addition, replacing sick leave with paid leave was standard procedure in Japan because it was a sign of loyalty and commitment. Kelly was expected to follow suit and sign the papers. The loss aversion principle influences decision making significantly. Preferences depend on how the individual frames the problem. The problem can be framed to present the outcome as gain in which case the individual will be risk