The management of major courses is vital to curricula at specialized high schools, which were established to nurture vocational workers. The 2022 revised curricula, which was developed based on the high school credit system, was finalized and announced on December 22, 2022. Consequently, the importance of responsible education through guaranteed guidance for the minimum level of attainment is ever more growing. Research shows that teachers at specialized high schools are attempting to organize and manage major courses consisting of basic subjects and practical subjects; however, the rigidity in the supply and demand of teachers is hindering their efforts. Moreover, teachers are struggling to devise additional guidance plans for underachieving students, although they are providing guaranteed guidance for the minimum level of attainment by establishing selection criteria and guidance measures for these students. These findings suggest that more teachers need to be secured in the short-term, while detailed programs and guidelines need to be developed in the mid- to long-term. At the same time, capacity building strategies for teachers, such as seminars and training, need to be provided.