<p>This study examined the relationships among emotional vulnerability, hopelessness, and depressive symptoms in Japanese university students and tested whether hopelessness mediates the association between emotional vulnerability and depression. We also explored potential gender differences in mediation pathways. A cross-sectional online survey was conducted in July 2025 with 577 Japanese university students (278 men, 299 women; mean age = 20.5 years, <i>SD</i> = 1.78). Participants completed the Emotional Vulnerability, Beck Hopelessness, and Center for Epidemiologic Studies Depression Scales. Descriptive statistics, correlation analyses, and mediation analyses were performed using the PROCESS macro. Emotional vulnerability was significantly associated with hopelessness (<i>r</i> = .34, <i>p</i> &lt; .01) and depressive symptoms (<i>r</i> = .52, <i>p</i> &lt; .01). Regression-based mediation analyses indicated that emotional vulnerability was positively related to hopelessness (<i>β</i> = 0.34, <i>p</i> &lt; .001), which, in turn, was positively related to depressive symptoms (<i>β</i> = 0.34, <i>p</i> &lt; .001). The effect of emotional vulnerability on depression was strong (<i>β</i> = 0.52, <i>p</i> &lt; .001), with both significant direct (<i>β</i> = 0.41, <i>p</i> &lt; .001) and small but significant indirect effects (<i>β</i> = 0.11, 95% CI [0.08–0.15]). Gender-stratified models revealed different pathways; for men, the direct and total effects were stronger, whereas for women, the indirect effect via hopelessness was more pronounced. Thus, emotional vulnerability contributes to depressive symptoms through hopelessness, with notable gender differences in the underlying processes. These results underscore the importance of screening for emotional vulnerability and tailoring interventions to address gender-specific risk pathways to prevent depression among university students.</p>