Recently, I discovered a fun game called Osu; it’s a clicking game with beat maps to various Japanese songs from animes (or whatever else people submit, but it’s mostly Japanese). The goal is to click the circles as they pop up at the right time in rhythm/beat of the song. It takes a while to get the hang of it… it’s pretty crazy and some songs are ridiculously hard, but it’s also good if you want to improve reflexes. :P There’s hundreds of Beat maps with various difficulties you can download from their website. Anyways, I think it’s a fun break from studying if you’re looking for something to do. You can also set the language to Japanese.
Anyways, here it is: http://osu.ppy.sh/