A Japanese breed of dog called Kishu. He was adopted by Bincho-tan after he followed her to her house in the woods, after she gave him some food from a shop in the town. He was apparently a stray, as he had no collar when Bincho met him. He was given a collar made with one of the large nuts seen in the series. He was also given a kennel, made with one of Chiku-tan's inventions after it broke and failed to serve its intended purpose. After giving him a collar, Bincho decided to name him Saji, which, according to her means 'trifle'. Bincho explains to Kunugi, who was present with her at the time, that she chose 'Saji' because the dog had apparently been abandoned, as though it was just "a trifle".