This qualitative study investigates what authenticity can mean in debate class by understanding students` lives inside and outside classrooms in an alternative school. In this study, the following questions are explored: (1) What do teachers perceive as authentic in debate class? (2) How do students realize and experience authenticity while conducting public debates? (3) Can learning from classroom debates be transferred to everyday life? Through my insider`s view as a teacher at an alternative school, I observed the class sessions, interviewed the participants and recorded teachers` meetings as well as the students` debates. The teachers perceived public debates as an ideal example of debates outside the classroom and everyday debates among students as an actual text to be reflected. As students debated the real problems in their school lives, they were able to realize multiple authenticities beyond the teachers` expectation by constructing arguments and interacting with many participants. Learning from classroom debates was not directly transferred into the students` lives. However, by being empowered and by empowering themselves as active learners, students conducted debates meaningfully in their lives and were able to integrate their lives inside and outside of the classroom.