This study explored and clarified the process by which three-year-old children, who have recently entered kindergarten, change how they relate to other people, such as their parents, teachers, and friends and become accustomed to preparing for school, which is part of their new kindergarten life and routine. Data were collected using a video camera in a kindergarten class of three-year-old children. Three children were selected from the collected video data. Their behaviors were analyzed using the Ueno Style Qualitative Analysis Method. First, the finding showed that they gradually performed the morning preparation away from the adult, talked to their friends actively, and got ready in silence. This indicated a change in their relationship with others as they adapted to the preparation process. Second, changes in the way intentions are expressed were revealed. Children asked specific questions from the teachers, while asserting themselves through non-verbal expressions. Finally, the process of adaptation to kindergarten life was complex, as behaviors that were seen immediately after the children entered kindergarten in April, were also observed when the children were considered to have adapted to it.