kknull. Led by vocalist and guitarist KK. Null, jointly by means of guitarist Mitsuru Tabata and drummer Masataka Fujikake, the group was formed in Tokyo in 1987. Zeni Geva's noise has been variously described as noise rock, arithmetic rock, bereavement metal, thrash metal, sludge metal, doom metal and manufacturing metal.

Null's strong vocal delivery and influential attendance makes him a charming frontman.