This study aims to clarify what factors made and transformed ‘teaching style’ in physical education of Elementary School Teacher A through clarifying an overall picture of a life history of Teacher A. The results are summarized as following points. 1. Teacher A hold the following three ‘beliefs as school teachers’ when he was hired as a teacher of B Attached School teacher. Those were ‘meaningful teaching for pupils (belief as teachers)’, ‘It is most important to realize a classroom where all pupils could live and study without anxiety (belief for pupils)’ and ‘coexistence (belief for schools)’. Teacher A made his ‘teaching style’ under the category ‘chances of professional development as a school teacher within the ethos of B Attached School’. The categories consisted of ‘B Attached School as an experiment school’, ‘job as a classroom teacher’ and ‘support from a mentor’.