Objectives Community residents experience changes over time, including those in the care prevention system, governmental expectations, and their motivations. To support community-based prevention activities, it is necessary to clarify these changes. This study used a qualitative research method to examine changes in roles and feelings among "Kaigoyobou leaders" who had been involved in community-based care prevention activities for 10 years.Methods The study participants were nine leaders (six men and three women) who had been active in community-based care prevention for approximately 10 years. Through one-hour semi-structured interviews, we explored their current activities, reasons for taking the leader training course, changes in the content of their activities since completing the course, changes in their roles in activities and feelings about the activities, and what they recognized as important in their activities. Interviews were transcribed verbatim and analyzed using a modified grounded theory approach. From the transcripts, we extracted "concepts" related to changes among the leaders and generated "categories" to summarize the concepts.Results The analysis identified 28 concepts summarized into 12 categories. The categories included: "belief in the activities" (e.g., "focusing on preventive effects"), "learning through trial and error" (e.g., "learning continuously"), "developing the activities" (e.g., "expanding the activities"), "commitment to the community" (e.g., "valuing connections with people involved in the activities"), "increasing required roles" (e.g., "taking consultations from juniors"), "relationship with the government" (e.g., "responding to requests from the government"), "benefits from the activities" (e.g., "receiving a sense of accomplishment and satisfaction from the activities"), "burden due to the activities" (e.g., "a shortage of group members"), "aging of stakeholders" (e.g., "increasing age of the participants"), "preparing for continuity" (e.g., "new people wishing to participate"), "considering ending activities" (e.g., "reducing activities due to increasing age of the leaders themselves"), and "impact of the coronavirus."Conclusion Leaders' strong belief in their activities and their ability to adapt based on successful experiences were crucial. They responded effectively to environmental changes, including evolving government relationships. Fostering leadership belief, highlighting the benefits of activities, and supporting collaborative responses to environmental changes are essential for ongoing success.