To date, there is no evidence suggesting that a program aimed at increasing self-compassion is effective in interdependent cultures such as Japan. The aim of this study was to examine the effects of an Enhancing Self-Compassion Program (ESP) among Japanese individuals in a randomized controlled study. Individuals reporting low self-compassion (N = 40) were randomly assigned to an ESP or wait-list control group. Participants completed self-report questionnaires at pre-treatment, post-treatment, and a three-month follow-up. In the post-treatment and follow-up, ANOVAs revealed that the ESP group (N = 16) had significant improvements in each of the subscales of self-compassion (Cohen’s ds: .91–1.51) except for mindfulness, whereas the control group (N = 12) did not. Greater reductions in negative thoughts and emotions in the ESP group were also found. These gains remained at follow-up. These findings suggest that an ESP may be an effective and acceptable adjunct intervention for Japanese individuals with low self-compassion.