Jii-san hails from the manga *Dangerous Jii-san Ja*, created by Kazutoshi Soyama and featured in Coro Coro Comics. The character joins a commemorative crossover ensemble marking the magazine’s 40th anniversary, with the story unfolding within a lively elementary school backdrop, hosting dynamic interactions among Coro Coro’s beloved characters. While specific backstory, personality traits, or narrative arcs for Jii-san remain undisclosed, their participation emphasizes the project’s celebratory focus on uniting the magazine’s iconic figures across generations. No supplementary lore, alternate adaptations, or media expansions beyond the anniversary setting are documented, leaving the character’s original series context and broader role undefined. Jii-san’s presence is currently confined to this celebratory narrative, reflecting collaborative homage rather than individualized exploration.