The issues experienced by general teachers (GT) in instruction in an inclusive classroom in primary school are the difficulty of designing effective instructional strategies that can meet all students' needs with various uniqueness. This research investigates GTs' experiences of the brain's natural learning systems-based instructional approach in an inclusive classroom. The research involved ten teachers from ten inclusive primary schools in three cities in Indonesia. Data were gathered through observation in an inclusive classroom and open interviews. Qualitative data analysis is used to analyze data. The result found six major themes: learning motivation, learning experience, psychomotor, social skill, talent and interest, and general teacher competency. This study implied that teachers could develop their competence by designing effective instruction in inclusive classrooms to benefit all students. The instructional approach based on the brain's natural learning system can be used to manage inclusive classrooms to be more productive.