The forest under common ownership in the former Toriumi district (now in Daito, City of Ichinoseki, Iwate Prefecture) provides a case study to clarify the relationship between municipal mergers and forests under common ownership in terms of management vision and issues for the future. First, the former and current state of this forest is reviewed, followed by information on developments accompanying municipal mergers in the area. The study consisted of interviews, a questionnaire survey, and document and literature searches. Results revealed that: (1) management of the forest was slack despite common ownership practices in the past. (2) Upon a forest of 186 ha belonged to the district formally with municipal mergers, relevant parties agreed to merge management and operation of the district's forests. (3) The local population agreed to this move and was aware of the region's responsibility for its own forests but had limited awareness of the need for relationships with other bodies. And they expect a forest function of public benefit. Focusing on the varied roles of forests and studying usage policies intended a tie-up with other bodies are crucial issues that are intended to effectively utilize local resources like forests under common ownership.