With the outbreak of the COVID-19 pandemic, school curriculums that would have been considered abnormal have become a new trend in school education. Under such circumstances, this study attempted to examine the concept of blended learning and explore an implementation plan by constructing curriculums. Blended learning is a new approach combining both online and offline learning activities, including harmony between simultaneous and non-simultaneous interactions, course planning and selection of appropriate techniques. It is “the New Normal” that has been the mainstream for education in a post-COVID world. Based on a teaching model of the Seoul Metropolitan Office of Education, this study develops an implementation plan by analyzing the flow of blended courses and reconstructing curriculums depending on class type. The implications are as follows: First, it offers a clue for the design of balanced courses between online realtime two-way (contents- and assignment-centered) and conventional classroom-centered classes. Second, it is required to analyze the characteristics of online classes and develop their course strategies. Third, in online classes, teachers’ roles will vary from instructors to class facilitators. Therefore, there should be continued efforts to develop diverse types of courses for students in consideration of various types of blended learning.