Sasakia charonda is endemic to and was designated the national butterfly of Japan in 1957.
   One of the primary reasons that the Japanese Emperor was chosen as Japan’s national butterfly is its cultural significance.
   In Japanese mythology and folklore, butterflies are associated with elegance, beauty, and transformation. They are seen as symbols of love, happiness, and good fortune.
   The Japanese Emperor, with its majestic appearance, perfectly embodies these qualities, making it a natural choice for the national butterfly.
    They are most commonly found in the upper canopies of forests, only coming down to feed or to find salt and mineral sources (puddling).
   The adult flight season is from June to August
   Males are quite territorial and fly over trees to search for intruders, and even chase birds such as sparrows to protect their range.
   The dorsal side wings of male Sasakia charonda display a striking blue iridescent coloration, accentuated by white, orange yellow and red spots, as well as by brown margins.
   The ventral side wings also have a variegated, but somewhat more subdued, pattern. 
   They are distinctly sexually dimorphic, with the dorsal side wings of the slightly larger female lacking the brilliant blue purple iridescence of the male.
   * Despite the vibrant patterns on their wings, they have transparent sections that help with camouflage when amongst vegetation.
   * *As with all blue butterflies, the blue coloration is not caused by pigmentation, as blue pigments do not exist in butterflies, but by structural coloration, with the color being derived from light refracting off the thousands of dorsal side wing scales. (This is a very effective predation defense, as when they fly under leaves or branches, and are cut off from sunlight, their dorsal wing color immediately loses its blue coloration, causing predators to believe that the butterfly has disappeared.)
   Potential predators include birds, rodents and arthropods.
   Sasakia charonda is an effective pollinator, often found fluttering around various varieties of plants.      They are primarily attracted to the vibrant colors and shapes of flowers.
   While they feed primarily on nectar, they inadvertently collect, transfer and redeposit pollen, on other plants, contributing significantly to the pollination process.
   * * * As members of the Brush Footed (Nymphalidae) family, they use their pair of shorter front legs for food tasting, and their two pairs of longer rear legs for propulsion.