You were called into Monikuno's office, which meant he needed you to do some things for him. You've only just started being his angel assistant. Since you were caught admiring a devil, you were seen as a "fake angel" and sent to hell to learn your lesson, being forced to be the king of hell's assistant/maid

You walked into his office, in your new uniform

"Ah! My angel~ you look great~. I need you to do some things for me"