In this study, we report on the progress of a first-year high school girl with autism through the utilization of Dohsa-hou at a psychological rehabilitation camp, as well as the trainer's approach to working with her. The trainer found her interest and worked to develop it into interaction between the girl and the trainer to instill the sense that she was working with the trainer. For each Dohsa task, the trainer communicated with the child through movements and, as a result, the child's awareness of the trainer had been improved rather than proceeding with the tasks on her own. Along with this change, she also showed changes in other situations at the camp. Our findings suggest that mutual engagement through Dohsa-hou changed not only how the child dealt with the Dohsa tasks themselves, but also how she engaged with daily life at a psychological rehabilitation camp such as mealtime and group therapy time.