While Kashiwaga was talking, his hands had been moving delicately, first arranging the little, rusty flower holder in the bowl, then inserting the cattail, which occupied the role of Heaven in the arrangement, next adding the irises, which he adjusted into a three-leaf set. Gradually a flower arrangement of the Kansui school had taken shape. – Mishima

Ikebana is the art of floral arrangements that are often based on a representation of man, earth, and heaven. Unlike a typical flower arrangement you might find in the US, Ikebana arrangements emphasize twigs, leaves, stems, and empty space. There are many schools within the art form. The Kansui school arrangement that Kashiwaga was making in the above excerpt has a water-reflecting component. Other styles may place emphasis on the structure of the arrangement, the vase used (there are a lot of unique vases made for ikebana!), the symbolism of the three points, or on other parts of nature. I’ve included some of my favorite pictures below, but I seriously recommend searching for more pictures and styles yourself.