In the early 2000s, Germany experienced a so-called “PISA shock”. This was treated as a serious social problem, because PISA revealed the low educational performance of immigrant students in Germany in comparison to other countries. It also revealed a serious performance gap between immigrant students and non-immigrant students. These problems were discussed from the aspect of immigrants’ social integration. Since 2003, the school system has been radically reformed. Germany had been one of the few countries in Europe that still maintained the half-day school system. In this system, school ends by 1 pm or earlier, and three areas—school, home, and outside school—are recognized as partners, sharing the role of education equally. The half-day school system and the clear sharing of educational roles among these three areas were the traditional norms and concept of education in Germany. However, in order to reduce the performance gap, in recent times the school day has been expanded to the afternoons through an all-day school policy. This policy introduced a new school system, the so-called “all-day school” system. Under this system, school ends around 4 pm. This paper analyzes this school reform from the viewpoint of the changing relationship between school, home and outside school in education. This paper focuses on the case of Haydn School in Bremen. Bremen is one of 16 German Länder that introduced the “unique” all-day school policy. All-day schools are categorized into 3 types by KMK, but Bremen focused politically on only one type, namely, the “all students are obligated type”. This school system obligates all students to stay in school until 4 pm for more than 3 days a week. In order to reduce the performance gap, the “obligation type” system has been widely implemented in Bremen. The fieldwork in Haydn School was conducted during the transition period of the policy (2007-2009) and also in the consolidation period (2015-2018). First, this paper analyzes the relationship among the three areas (school, home, and outside school) historically. Next, the meaning of this changing relationship is discussed taking into consideration today's situation. Analysis of this research shows that the introduction of the all-day school system has diminished the meaning of the separate roles for the three areas. Drawing out a clear role for each area is no longer possible in the “obligation type” all-day school system. This paper suggests that the traditional norms of education in Germany are being questioned because of the increasing number of families with diverse backgrounds. These families are not familiar with the “German educational tradition.” The widespread introduction of the all-day school system in recent times has led to the reconstruction of the methods and concept of education in Germany. Under the all-day school system, education is now described as an interaction among diverse areas, working together, and coordinating those diverse areas based on the school. This phenomenon suggests that the framework supporting children's growth in Germany is now changing fundamentally.