Wikipedia
is a school of Ikebana, or Japanese floral art.
Sōgetsu typically uses either a tall, narrow vase such as one made from a bamboo stem, or a flat, open dish in which the flowers and branches are fixed in a hidden kenzan spiked support. However, other forms are possible, including highly elaborate creations that fill an entire hall.
One of Sogetsu's central ideas is that an arrangement should have three strong elements, each with certain proportions and arranged at a certain angle. But there is considerable latitude to work with whatever materials are available and to express the spirit of the moment.
The school was founded in 1927 by Sofu Teshigahara. It is currently led by Akane Teshigahara, the founder's granddaughter. Noted practitioners include Master Instructor Koka Fukushima, whose masterclasses worldwide have received acclaim in floral art circles.