Iou is a ninja tool inventor based in Konoha, assisted by his partner Shoseki. He's best known for creating weapons that are either impractical to carry or just plain useless—fans often joke about his complete lack of concern for actual combat utility. The frequent explosions from his workshop earned him a spot on the village outskirts, though Iou insists these accidents are just part of the creative process.
When Team Guy (with Naruto filling in for Rock Lee) stops by the Konoha Research Lab to stock up on supplies, they find Iou and Shoseki deep in the basement working on something new. Two rogue ninja named Gameru and Kusune show up demanding fresh weapons—they're already carrying a couple of Shoseki's previous creations. Iou hands Tenten his latest invention, the Jidanda, and it actually works well enough for her to take down both attackers. The moment the fight ends, though, Iou reclaims it, muttering that it needs more refinement.
Years pass. After the village gets destroyed, Tenten and Neji Hyūga make their way back to the research lab to gather whatever tools they can salvage.
Content compiled by AnimeList.moe from publicly available sources.
