Issun Nanashi is a supporting character in the anime series 'Ookami-san to Shichinin no Nakama-tachi.' He is based on the fairy tale character Issun-boushi, the One-Inch Boy. Issun is a tiny, energetic, and often mischievous boy who serves as the narrator of the series, providing humorous commentary and breaking the fourth wall. His playful personality and witty interjections add a unique charm and comedic relief to the story, guiding viewers through the unfolding events.