Mondai and his buddy Poccha showed up in Konoha with a pretty straightforward goal: steal some ninja secrets to bring back home and impress their village. They figured the added prestige would score them missions and, more importantly, attention from the local women. Nobody's quite sure where their village actually is—could be somewhere in Fire Country, could be in some non-shinobi nation nearby.
Since neither of them had any real training, they went with the low-tech approach: costumes. Mondai dressed up as Maito Gai, and they managed to fool a few people, but Kakashi saw right through it immediately. He tipped off Tsunade, who decided to have some fun with the imposters. She sent them on a series of deliberately awful, backbreaking missions with Sakura, TenTen, and Katsuyu tagging along to make sure they suffered. Poccha and Mondai stuck it out, hoping to earn Tsunade's favor.
The main problem was Naruto. He completely bought the disguise and actually trained with them, which definitely wasn't part of their plan.
Eventually the two gave up and headed out of the village, only to run straight into the real Gai and Lee coming back in. Gai and Lee were understandably confused, and when Poccha and Mondai tried to fight them, things ended pretty quickly—a couple of kicks sent the imposters flying. That was the end of that.
Content compiled by AnimeList.moe from publicly available sources.
