A chinese commercial ship wrecked at the offshore sea of Shizuoka in 1826. The rescuees presented kinkan fruits preserved in sugar to rescuers. The seeds was raised to plants and they spread throughout Japan.
Chisa is covered with frost. Frost is the solid deposition of water vapor from saturated air. It is formed when solid sufaces are cooled to below the dew point of the adjacent air. (from Wikipedia, English)