Wings Stadium, a dim, beery sports barn in Kalamazoo, Mich., is an appropriate home for the K-Wings minor-league hockey team and the Killamazoo Derby Darlins. Yet every year, in June, the site hosts a spectacle more uplifting than a season of flip checks. This is when it is the setting for the graduations of the city’s two main high schools. A couple of nights after Kalamazoo Central High fills the arena, it’s Loy Norrix’s turn. The rink is covered, and students, friends and family take over most of the 5,100 seats.