The development of a mind-reading ability, known as theory-of-mind (ToM), has been recognized as following a universal process, but the age at which the false-belief task is passed has been reported to have wide inter-group variabilities. Japanese children have been reported to acquire a false-belief understanding at a slightly older age than their western counterparts. The present study investigated the extent to which Japanese-children's understanding of ToM could be brought forward by using perspective-shifting training in conversational discourses. Japanese children aged 4.5 years-old, but not 4.0 years-old, improved their false-belief understanding after the training. However, this improvement was limited to their understanding of representation-change. Although it is hard to isolate the influence of language experiences and socio-culture aspects, training with perspective-shifting discourses in interactive contexts was effective in enhancing the development of mind-reading for 4.5 year old Japanese children.