Kotekote is a sub-genre of visual kei that is described as "traditional visual kei." In looks, they usually wear elaborate detailed costumes and extreme hairstyles.
According to one Japanese fan-page, Kote kei incorporates three ideas: seeking the bizarre, decadence, and aesthetics. Common themes include roses, crosses, corruption and blood.
According to another Japanese fan-page, there are two sub-genres of kotekote - black kei and white kei. Black kei has dark feelings to the rhythm and speedy melodies, white kei aims to be more melodious and transparent.
Kote kei is sometimes written as kotekote visual kei, kotekote kei, or just kotekote or kote.
An example of a kote band is X Japan.
Info from urban dictionary, image from deviantart.