Japanese (Hiragana): ろうそく 

Candles have been and still are a popular item to incorporate in kinbaku and ties. 

The most common and seen use is: Rōsoku zeme (ろうそく責め), this is dripping candle wax on your models body.

Another is: Rōsoku tengu (ろうそく 天狗), sticking a lit candle in your models vagina.

See also: Warōsoku, Tengu shibari