20th-century Japanese school of floral art that introduced the zen'ei (“avant-garde”) ikebana style in which freedom of expression is preeminent. Founded by Teshigahara Sōfū in 1927, the school rose to prominence after World War II. It appeals to contemporary tastes by largely disregarding the classic formal rules; containers of any shape and material are used, and man-made materials are incorporated into the arrangements together with the flowers or plants.