Ikebana often means setting whatever materials are at hand in a given space. Study groups are like this - you never know what is available beforehand.
What kind of flowers, what kind of vase will you be given? You won’t have the answers to these questions until you arrive. You create your ikebana from this coincidental encounter.
This kind of coincidence is quite special - you never have exactly the same opportunity presented twice. The question is how to optimize the situation.
The result must be natural, as if it were expected all along. We cannot judge the material - saying how happy we are that this particular flower was provided, or lamenting that we didn’t have that certain flower. We work with what we have - this is the essence of ikebana.
From “Teshigahara Sofu: Kadensho”