Teachers plan and execute lessons. As teachers, improving teaching expertise is meaningful and important. Recently, group efforts have been made to improve teachers' teaching expertise at the school level, and an example of this initiative is the teacher learning community. In H Elementary School, the teacher learning community in the school sought to student-centered instruction direction through curriculum and class research. They implemented a teacher learning community that focused on classes with fellow teachers and external experts. The purpose of this study was to analyze what teachers who participated in the teacher learning community in schools noticed in class activities and reported the experiences of cooperation among teachers in the process. We analyzed the fact that teachers paid attention to the class in the process of cooperation through the data of the workshop of the teacher learning community workshop. The study found that H elementary school teachers was confirmed that the noticing to the largest share in lesson planning and execution, and they shared the purpose of commonness aimed at class and the purpose of class centered on students despite the difference in teachers' opinions and the obstacle of individual difference. In addition, it was found that teachers were noticing the necessity of a class-centered teacher learning community by cooperating with teachers and external collaborators for student-centered classes. Through this study, We expect concrete research for teaching expertise through the attempts and attention learning of the teacher learning community that sees classes on an objective basis.