Researchers have started to apply games to education recently. Teachers can use computers to understand and manage students' learning statuses. However, games are seldom designed and used for teachers, who play important roles in the learning process. This study therefore applies the concept of a management game for teachers using students' learning portfolios. Furthermore, this study creates an environment that teachers play the role of gardeners and who grow and take care of trees which represent students. Many of teachers have never shared game experiences to students which may cause the gap between students and teachers. This study aims to clear up the gap between students and teachers through game-based teacher management system, and also to create a game interface for teachers to visualize students' learning profiles and interact with students.