Pronunciation is often a difficult hurdle for many Japanese students. In order to encourage students to practice pronunciation is important for them to have a source of input outside of the class. This website offers a wide range of activities that give examples visually as well as through listening activities. Since this website has a lot of Japanese written in its instructions, it will not be too daunting for Japanese high school students. I think that this website works best when used in tangent with lessons that introduce and practice the concepts presented.
Konan University Pronunciation Website