Leadership in today's world requires new leadership values. No longer is a leader simply a person who can make a good and inspiring speech. Convincing people to make positive changes such as changing our habits to better sustain the earth on which we live is the job of the true leader. The purpose of this study was to obtain an overview of the principal's leadership style, teacher performance, the principal's efforts, and the principal's barriers to improving teacher performance of the Japanese school teacher, Mejobo Suci Kindergarten. This research is a descriptive study with a qualitative approach involving Research subjects: principal and 5 teachers. The technique used in the research is a survey using interviews, observation and documentation study as primary data collection tools. The results showed that the principal was predominantly applying a transformational leadership style, this style was able to improve teacher performance, the efforts made by the principal in improving teacher performance through coordination meetings, providing direction and guidance in carrying out their duties. Meanwhile, the obstacles faced are the lack of inadequate school facilities and infrastructure. Therefore, right leadership brings co-ordination among teachers which helps in effective work and attainment of organization goal and as motivated teachers are willing to give their 1005 effort.