This paper reports how the author developed a pedagogical practice in the undergraduate elective course “Japanese Grammar,” which is an approved credited course intended for teachers of Japanese as a foreign language and teachers of Japanese as a native language. While this course is not specifically aimed at those learning Japanese as a second language, it does not prohibit such students. Although it is mainly intended for students enrolled in teaching programs, many international students who sought a deeper understanding of Japanese grammar also took the course. Therefore, the author intended to develop a curriculum to critically reevaluate the way grammar is taught in schools, which lead to the discovery of a new grammar system for international students, called “School Grammar”.