Persona Q: Shadow of the Labyrinth Side: P3 Vol. 1 (manga)

A WONDROUS MAZE: After the sudden cancellation of their school's cultural festival, Gekkoukan High School's own S.E.E.S. look to relieve some stress by beating some shadows in Tartarus. But a visit to the Velvet Room beforehand takes an unexpected turn, and they find themselves stuck in a high school that they've never seen before. To return home, they'll have to make their way through the treacherous, shadow-filled corridors of a most curious maze. Luckily, they'll have some help from two mysterious students and a few other Persona users?