Japanese non-native English-speaking EFL (English as a foreign language) teachers in secondary education (JEFL teachers) work in a different educational context from language teachers in Europe. The purpose of this exploratory research is to identify the distinctive ways in which JEFL teachers think, know, believe and do. These concepts are subsumed under the general heading of JEFL teacher cognition, particularly as this applies to teaching and teacher education in Eigo Kyoiku (English education in Japan). The overall purpose of exploring JEFL teachers’ cognitions is reflected in four research guiding questions (RQs): 1) to identify the nature of JEFL teacher cognition; 2) to see any particular influences that might help shape JEFL teacher cognition; 3) to learn to what extent JEFL teachers’ cognitions are consistent with their actual practice of teaching; and 4) to discuss the ways in which the concept of language teacher cognition (LTC) may be understood and situated in the Japanese context. The research consisted of two studies: a) a quantitative Preliminary Study administered to 62 JEFL teachers and 81 modern foreign language (MFL) teachers in Scotland, in order to identify any areas regarding JEFL teacher cognition; and b) an in-depth Main Study based on a qualitative and ethnographic approach, featuring 10 JEFL teachers. This made use of qualitative data analysis and the applied KJ method, and also drew on complexity theory, through reflective and reflexive processes with particular reference to retrodictive qualitative modelling (RQM). The results of the Main Study are presented as 16 concept maps, each of which represents a featured aspect of JEFL teacher cognition (ATC). It represents the signature dynamics of each ATC and points to the variation and tension which JEFL teachers experienced in relation to each ATC. The research suggests that, although LTC have certain universal characteristics, it needs to be explored on the assumption that it is situated socially, culturally, locally and personally.