Tumor suppressor gene p53 knockout medaka has been generated. The tumor spectrum of this medaka model, however, remains unknown. In this study, we performed individual time series analysis of p53 knockout medaka using a 14.1T MR microscopy. Extracting size change of kidney of the medaka model, we found early indications of disease and difference in phenotype due to location difference of point mutation in the p53 gene. Since p53 knockout medaka showed rather large variations in kidney slice, importance of individual time series analysis was confirmed.