Crack6 (crack six) is a rock band to which Chisato of PENICILLIN was mainly formed in 2003.
The belonging office is euclid agency. The CD release is Beat Art Recordings.
At first, it started as Chisato's solo project. In the name in Crack6, Chisato is MSTR, and Shigemori is SHIGE. Members other than MSTR and SHIGE are fluid.