This article explores the transition of cooperative co-parenting during the divorce process. Eighteen parents, representing eight co-parenting pairs and two individuals who had just undergone mandatory mediation for parents applying for separation, participated in the study. Through in-depth interviews with parents who were classified as cooperative during the mediation process, we examined how they reason and the struggles they face during the divorce transition. The study applied a sociocultural perspective, focusing on the cultural ideals of equal parenthood, and used the concepts of boundaries and shared care as analytical tools. A main finding is that maintaining cooperative co-parenting requires hard work, even in no-or low-conflict divorces, but the parents do it for their children. The results showed that the transforming process involved efforts to (1) continue established parenting practices,(2) shield the children and (3) deal with their own emotions. The underlying premises for successful co-parenting are trust in each other's ability to take care of the children and their own knowledge of the emotional bonds between the children and each parent. In turn, these premises motivate parents to manage their own emotional turmoil.