Kindergarten supervisors face great challenges when dealing with the negative emotions felt by preschool staff during curriculum restructuring, as changes implemented to deal with the declining birth rate and resultant social change increase the staff workload. Few studies of co-learning communities have focused on emotional aspects, particularly on knowledge management. This study aimed to explore how teachers’ negative emotional responses were transformed through a co-learning community of four kindergartens during the process of innovational curriculum reform. Thirty participants were involved in this study, including 26 teachers, 4 principals and 2 external leaders. The data collected over a three and half year period included community interactions, teachers’ reflection notes, interviews, participant observations, etc. The main findings are: (1) The co-learning community across the four preschools, in conjunction with the community within each preschool enhanced the emotional awareness of both the principals and the teachers, and their capability to reduce negative emotions, (2) The broader co-learning community, drawing on the teaching practices of each staff, helped enhance the principal’s ability to care for the teachers’ negative emotions and thus played a major role in the staff’s ability to transform their emotions. (3) Three different models were identified during the process by which principals could foster positive emotions in their organizations.