It is the biggest video sharing site in Japan.
Latest otaku culture exists there.
I will show you the popular movies top 5.
(However,you need niconico ID to see the video,
so I paste the copy video on Youtube)
the 5th 9,400,000PV in niconico
Hatsune Miku is vocaloid which is computer programed virtual singer.
the 4th 11,200,000PV in niconico
Miku miku ni shite ageru(Hatsune Miku)
the 3rd 11,600,000PV in niconico
Is Ronald crazy about dance?( Ronald McDonald)
His permformance is very psychedelic.
the 2nd 14,100,000PV in niconico
Let's go Onmyoji(Gouketsuji Ichizoku)
promotion video of PS2 Fighting game.
Onmyouji is a ancient professional practitioner of the Japanese esoteric cosmology.
They sing, dance and fight in the game.
the 1st 18,100,000PV in niconico
Bad apple! (Touhou)
Touhou is the most popular indie game in Japan.
The characters dance with the music of game.
All of them are music videos, so if you canot understand Japanese, you can enjoy!
初音ミク Tony ver. (1/7スケールPVC塗装済み完成品)