Early in 2016, the Convention on the Rights of Persons with Disabilities was enacted in Japan. It made the establishment of an inclusive educational system a national priority and required Japanese schools and teachers to accommodate individual needs of students with special needs in schools. An adequate balance between individual and group needs has been challenging for classroom teachers dealing with behavioural needs of individual students while teaching a whole class. A traditional Japanese approach to teaching a lesson in regular classes has been aligned with and supported by the lesson study approach, whereby schools engage in professional development activities. These activities focus on cooperative planning and monitoring of students’ learning progress in the selected curricular content over a school year. As part of lesson planning and preparation of instructional supports, teachers design and anticipate peer interactions among classmates. This social focus contrasts with the English-speaking countries (e.g. the USA, the UK, and Australia). For example, the use of school-wide positive behaviour support to improve student behaviours in English-speaking countries has been treated as an efficient foundation for including individual students with high needs in school. In Japan, there has been an increasing interest in this behavioural approach as a potential solution for addressing the requirements defined in the newly enforced law. It is proposed that mutually informed integration of the culture- and value-based practice of traditional lesson study with school-wide behaviour support can become a culturally appropriate approach to behavioural support.