It is commonplace in Japan for students in formal education to receive additional English tuition that is provided outside of regular school hours and typically for a fee. Such English Private Tutoring (EPT) (Yung & Bray, 2017) has largely escaped the attention of researchers, though recent studies have sought to investigate its role in language education (see Yung & Hajar, forthcoming). In this presentation, the focus is on the role of juku (cram schools) and yobikō (preparatory schools) in preparing students for high-stakes university entrance exams, which is one of the well-established functions of EPT in Japan. The discussion is framed in terms of test washback, that is, the effect(s) that tests have on learning and teaching. Within this theoretical framework, the key findings will be synthesised from the available studies that have investigated learning, teaching and assessment of English in juku and yobikō. Based on these empirical studies, the presenter will illustrate how exam content drives teaching and learning within EPT and how narrowing of the curriculum in EPT can affect teaching and learning in mainstream education. The presentation will be concluded with a call for further research into this much overlooked area of education.