Hijōkaidan (非常階段, emergency staircase) is a Japanese noise and free improvisation group with a revolving lineup that has ranged from two members to as many as fourteen in its early days. The group is the project of guitarist Jojo Hiroshige (JOJO広重), its one constant member, who is head and owner of the Osaka-based Alchemy Records. Other regulars include Jojo's wife Junko and Toshiji Mikawa (also of Incapacitants).
The group began at the very end of the 1970s as a performance art-based group whose anarchic shows would often involve destruction of venues and audio equipment, food and garbage being thrown around, and on-stage urination. As the group's lineup changed over time, their focus became less performance-based and more musically based, fine-tuning their sound into a dense wall of noise.