This paper reports a project in which researchers at universities in Japan explored the use of Mobile Assisted Language Learning (MALL) practices by developing a learning module intended to help improve students' scores on the TOEIC Listening and Reading Tests. MALL practices are currently being developed at universities in Japan because almost all students have mobile phones, many of them have had informal learning experiences with mobile devices, and students are integrating the communication and information gathering capabilities of mobile technology into their own lifestyles. The private nature of mobile phone communication may create barriers when students are asked to use personal mobile phones for school-centered learning activities. In this study a Nintendo DS mobile was used because it was affordable and students were familiar with this device for game playing and learning activities. In addition, because this device does not have the same telephone, messaging, and Internet functions that have made mobile phones an integral part of students' private lives, a device such as the Nintendo DS may be a neutral mobile platform for the development of MALL activities which could later be adapted and transferred for use on private mobile phones. The primary aim of this study was to discover whether certain MALL practices would foster an advanced form of self-study, self-regulated learning (SRL). In SRL students take responsibility for arousing and sustaining their own motivation in order to make, carry out, and evaluate strategic learning plans. It was concluded that the use of the MALL learning module encouraged study without teacher intervention, i.e., self study, in terms of time spent on learning tasks, levels of satisfaction derived from the tasks, and self-measured achievement. Furthermore, SRL was observed in terms of the specificity of the goals, the customized creation of learning tasks and their in-class applications.