In his old school, John acted like a tyrant and grew worse, Claire did her best to stop this behaviour. She gathered the whole school to stop him, which made John feel used and betrayed.
Thanks ヾ(❀╹◡╹)ﾉ~
He thinks that she betrayed him because Adrion overheard her tell someone that she was just using John to someone and Adrion told John. In reality, she did say it, but she said it just so that she could get someone to help her bring John to his senses not because she meant it.
Ok someone can explain what Claire did to John ? I didn't understand at all ;-;