I made warabi-mochi the other day for the first time. It's kinda like a Japanese jello-like sweets, made out of warabi-starch (arrowroot starch) instead of rice, which mochi is usually made out of. Warabi mochi is a specialty of the Kansai region and usually is a summer food, often served chilled or frozen.
It is served with kinako (roasted soybean flour) and kuro-mitsu (brown sugar syrup.) It is a very Japanese-tasting treat.