草書 (Jp: sōsho; Ch: caoshu)
Similar to Western shorthand, cursive script may have appeared as early as 200 BCE out of a need for a rapid, simplified way of writing clerical script. Cursive script was used chiefly for private and informal communications as well as for poetry.
The shapes of the characters are greatly abbreviated and sometimes altered to such an extent that they do not resemble the standard forms. Brush strokes are wave-shaped and made rapidly. The difficulty of reading this fluid script is further increased because several characters are often vertically connected without interruption.