Peonies were imported from China for their medicinal purposes as well as their aesthetic beauty, and the healing associations only made the royal flower all the more auspicious. In irezumi, peonies are paired with shishi (guardian lions) not only because both hail from China, but also because there's a story that a shishi was cured of illness by eating a peony. The flower can be paired with tigers, too. Like the peony, that animal came to Japan from China, and also has medicinal properties.
Note that the Japanese language uses the same word (taka) for both falcons and hawks. The visual difference is that falcons have a notched beak, while hawks do not. Taka are strong, with a piercing gaze. This explains why the bird has long been a symbol of the samurai , and the bird of prey is a common design on men's kimono. In irezumi, the bird of prey is paired with snakes, with the taka either swooping down to seize the snake in its beak, or with the reptile wrapped around its body. It's a depiction of killing or being killed. Thematically, the motifs is much deeper. The taka represents power, and the snake is longevity . The bird is also auspicious . Dreaming of a taka, Mount Fuji, and an eggplant on the first day of a new year is considered lucky. In the dream, the taka represents strength, power, and the ability to fly high .