Hybrid cognitive behavioral therapy (CBT), combining group and individual sessions, for treating obsessive–compulsive disorder (OCD) has rarely been examined in routine clinical practice. This prospective observational study preliminarily evaluated the feasibility and acceptability of a hybrid CBT program implemented in Japan. The program consisted of one pre-treatment individual session, eight group sessions, and one post-treatment individual session. Feasibility and acceptability were assessed using dropout rates and written questionnaire feedback. Twenty-eight individuals (mean age = 36.1 ± 14.0 years) participated, with two dropouts. Seven participants reported that the program duration was too short, whereas the remaining participants considered it appropriate. Nineteen participants indicated their willingness to participate in a similar program. Open-ended feedback highlighted the importance of group composition and program content. Self-Rating Yale–Brown Obsessive Compulsive Scale scores decreased at Session 8 (estimate = −2.74, p = 0.002) and post-treatment (estimate = −4.16, p < 0.001) according to a linear mixed-effects model. Reductions were also observed in Sheehan Disability Scale, State–Trait Anxiety Inventory, and Clinical Global Impressions Scale scores, whereas Center for Epidemiologic Studies Depression Scale scores showed no significant change. These findings suggest the feasibility and acceptability of the program and may inform future program development.