Pop'n Music (ポップンミュージック), most commonly shortened to Pop'n, PM or PNM, is a music video game in Konami's Bemani series. The game is notable for its bright colors, upbeat songs, and cute character graphics. Although Pop'n Music was originally intended to be played by couples on dates, it has greatly escalated in difficulty since early iterations, and has since then attracted many players of Beatmania and other Bemani games.
Source: Wikipedia, "Pop'n music", available under the CC-BY-SA License.
Only available for the PlayStation 2 (as the Arcade versions always contain all previous music), Pop'n Music Best Hits collects the best songs from the previous Pop'n Music titles (1-6).