The Japanese word yutori is commonly used. Previous research has reported that yutori of the mind is essential for a happy life. However, most of the results included in previous studies were obtained without empirical data. Thus, to find broader knowledge about yutori, we conducted an empirical study on the relationships between yutori and depression, anxiety, optimism, and pessimism. We presented 62 healthy Hiroshima University students with questionnaires. The questionnaires consisted of the yutori of mind scale, the State-Trait Anxiety Inventory, the Center for Epidemiologic Studies Depression Scale, and the Optimism and Pessimism Scale. The correlation analysis indicated that yutori has negative correlations with depression, anxiety, and pessimism. In contrast, a positive correlation was found between yutori and optimism. These findings provide a strong evidence for the notion that yutori of mind is positively related to mental health.