LAFAYETTE — Ninja followers know Geoff Britten as the guy who became the first American Ninja Warrior in 2015 by virtue of being the first competitor in seven seasons to complete all four stages at the season finale. This summer he will have a different focus in the Ninja world. Four months ago, he moved here from Maryland with his family to work as the creative director for Ninja Nation, a Colorado company that will open the first of 100 planned gyms across the country in Lafayette on June 30. Britten’s job is to oversee the design of all of the “arenas,” including layouts and obstacles. “Opening these gyms is so exciting,” Britten said last week while leading a tour of the Lafayette facility as a handful of mini Ninjas gave the shiny new obstacles a few trial runs.