This study aimed to explore specific ways of connecting people living with developmental disabilities (PLWDD) to companies by using a work transition support provider. As a result of conducting an ethnographic study at center A, it became clear that the implementation of work transition support that connects companies and PLWDD is a process of deepening the self-understanding of PLWDD through repeated training and reflection, and of deepening supporters’ understanding of this cohort’s characteristics. At center A, through a process of repeated training including daily classroom lectures, work, and practical training, supplemented by a review of training through interviews, a system was built that would deepen the staff’s understanding of PLWDD characteristics, and the cohort’s self-understanding. Further, what was particularly emphasized as part of the implementation was to find strengths, based on the strength perspective, which can be regarded as advantages to be utilized in the workplace. The aim was not only to compensate for weaknesses but also to make use of the strengths to lead to employment. Strengths were identified through repetition of the five methods, namely, acquiring skills, information gathering, reflection, reframing, and dialog, and characteristics were shared as strengths that could be used in employment.