Jii-chan is a supporting character in the anime Uchū Nanchara Kotetsu-kun: Ukkari Detekita Uchūjin o Sagase! and is the grandfather of the protagonist, Kotetsu. He is an elderly anthropomorphic animal character who is presented as an enthusiastic and warm-hearted figure. His background is closely tied to his role as a family member, living with or near Kotetsu and taking an active interest in the boy's ambitions. His primary motivation is to support Kotetsu's dream of becoming an astronaut and exploring space, often expressing excitement and encouragement. Within the story, he appears as a gentle source of guidance and comic relief, offering lighthearted advice and cheering on the young characters during their adventures. His key relationship is with Kotetsu, marked by affection and pride. He also interacts with other members of the Animal Space Academy community, but his connection to Kotetsu remains central. The character does not undergo significant development over the course of the series; he maintains a consistent role as a reliable and uplifting presence. Notable abilities are not emphasized, but his enthusiastic demeanor and unwavering support for Kotetsu are defining traits.