Grit refers to a non-cognitive trait that is characterized by perseverance and passion for long-term goals. In this study, we developed a Japanese version of the Grit Scale and examined its reliability and validity. A confirmatory factor analysis indicated that the Japanese version of the Grit Scale had two factors corresponding to the original version (study 1, 2, and 3). The results indicated that the scale has high reliability (study 1 and 3). Grit was positively correlated with conscientiousness (study 2 and 3) and self-control (study 3). Nonetheless, grit demonstrated predictive validity of longitudinal persistence and success measures over conscientiousness, self-control, and intellectual ability (study 3). These results are consistent with previous studies and support the reliability and validity of the Japanese version of the Grit Scale.