Calling Karaoke "popular" in Japan is like calling water "wet." Places where you can rent your own Karaoke room (for small or large groups) cover Japan's metropolitan landscape and nearly every bar has an aging Karaoke machine that sees nightly use.
So of course, Karaoke video games are nothing new. However, most Karaoke games only include the songs on the disk and/or those you can buy online for a dollar or two. This is not the case, however, with Joysound Dive as it provides you with over 90,000 songs (with more added monthly) for the low price of 1000 yen ($11.05) a month.