Bemani games are all the rythm-games like Beatmania, Pop'n Music or Dj Max. (I don't really know if DDR is a Bemani, I think so)
I think this should be fine, because I saw TLers like K-Music, and Bemani music(mostly DJ Max actually as the devlopers are from Korea)
They are pretty hardcore, you can also think of them as the ancestor of DJ/Guitar Hero/Rockband and all thoses Rythmn Games. Classic configuration is 3 upper black buttons 4 white buttons and something you can scroll either left or right(damn can't give a name to this Q_Q)
Here are some videos :
As you may think, they are arcade games.
But THANKS GOD There are emulators, the most known is probably Lunatic Rave, wich you can add skins(there are pleeenty of them), before there was ez2on, but it don't exist anymore. DJ Max have portable versions on PSP, wich are actually pretty good(they have the same gameplay as Portable Rock Band)
I guess this thread will be like the Osu! one, share song, maybe play online, play "who has the biggest one" with high scores, post videos etc...