The purpose of this study is to identify the current state of school-based after-school support in Japan and to evaluate programs providing such support, known as 'After-school Classes for Children'. This study focuses on the impact of After-school Classes for Children on children's everyday activities and their social and emotional development. The analyses were conducted based on data collected from questionnaire surveys targeted at elementary school children in Tokyo. The total number of children sampled was 5,307. The impact on children's everyday activities and their social and emotional development were identified from data analysis. This study also developed a scale for measuring the impact of 'After-school Classes for Children' on children's social and emotional development. Based on the results of analyses, it can be concluded that 'After-school Classes for Children', a program run by MEXT (the Ministry of Education, Culture, Sports, Science and Technology), is likely to contribute to the enhancement of the following two aspects of children's social and emotional development: 'Empathetic Understanding of Others' and 'Enhanced Interest and Ambition'.