KK.Null (born Kazuyuki Kishino) is one of the top names in Japanese noise music and in a larger context, one of the great cult artists in experimental rock. Starting his career in the early 80's by performing guitar improvisations in the clubs and streets of Tokyo, he continued by collaborating with Merzbow for two years, and joining the bands YBO² and Absolut Null Punkt.

In 1987, he gained wider notoriety as the leader, guitarist and singer of the trio Zeni Geva, which he described as "progressive hardcore". Zeni Geva reached world-wide fame with their heavy and hypnotic sound, eventually releasing three Steve Albini-produced albums on Jello Biafra's Alternative Tentacles label.

After playing the guitar as his main instrument for some twenty years, Null has gradually moved towards a more electronic approach. These days he mostly states the "nullsonic" as his primary instrument. Nullsonic is something of a variation of Robert Fripp's 1970's instrument "frippertronics" - a combination of electric guitar and effects units, which elevated the effects to equal importance alongside the guitar. Null has gone even further by discarding the guitar altogether and making all the sounds with effects only.

In recent years, he has concentrated his efforts increasingly on his solo material.