This study implemented a short-term practice of choral instruction using popular music while addressing students’ anxiety at a small-scale junior high school in rural Hokkaido, Japan, and examined its psychological effects among general students, including three with no prior choral experience (N = 8). Given that choral activities in Japanese junior high schools are not always motivating and that many students hesitate to sing due to anxiety and related discomfort, this study proposed an instructional approach that combined (a) a safe space for singing—defined here as a psychologically supportive environment that protects students from negative evaluation and encourages participation without fear of failure—and (b) popular music materials to increase engagement. Eight 50-minute practices were conducted with an emphasis on basic vocal exercises (breathing, posture, stretching) and supportive feedback to foster self-efficacy and cooperative practice. Pre-survey results indicated that 7 of 8 students (87.5%) reported anxiety about choir (“very much” 25.0%, “somewhat” 62.5%), with multiple reasons centered on technical concerns such as voice production, pitch, and lack of confidence. After the practice cycle, all students (100%) reported a positive change in feelings (“changed a lot” 25.0%, “changed a little” 75.0%) and rated practice as enjoyable (50.0% “very enjoyable,” 50.0% “somewhat enjoyable”). Regarding psychological changes attributed to choir (multiple responses allowed), 62.5% (5/8) reported decreased embarrassment and 62.5% (5/8) increased enjoyment; 25.0% (2/8) reported increased confidence and 25.0% (2/8) improved cooperation. Most students also reported a sense of accomplishment after the performance (87.5%, 7/8). These findings suggest that, distinct from competition-centered models, choral instruction that intentionally creates a safe singing environment and attends to student anxiety can support both vocal engagement and psychological growth in a short period, even in very small schools.