WAORYU, a Japanese Subculture broadcast station, released a video of how Japanese people enjoy their karaoke with cosplay, Ani-son and Otagei!
In this video, you'll see the "Cos-Kara" party footage. All participants are cosplayers and they sing Anime songs only at this event. Some cosplayers are also skilled at "Otagei", the dance style that is particular to anime and idol songs, and you see them do it with glow sticks in their hands.
Actual footage of the party starts around 1:45.
Opinions about Otagei are mixed depending on who you ask, but I have been to these parties in Japan and I'm telling you, it is addictive. Would you enjoy these parties?