Aseo-kun is a plump, yellow sweat sprite residing in Shizuku Forest. His family operates and lives within the forest's Sauna establishment. Known for his tendency to overeat and an extraordinary capacity for sweating, often described as sweating buckets, he particularly favors curry among foods. He interacts with other forest sprites, including Shizuku-chan and their friends. Aseo-kun appears in the original illustrated books, the *Pururun! Shizuku-chan* anime, and the *Picchipichi Shizuku-chan* anime. The spin-off *NiJiRo Fairy Shizuku-chan* reimagines him as human, retaining his core attributes.