The Unnamed Army and The Underage Girl

A young twelve year old girl visits a unique place where teenagers and young adults dress up in costumes and form bands and express themselves with their art. She finds out it's some sort of club, and falls in love with the idea of joining when she finds the website for it. The club is left unnamed and they call themselves the Unnamed Army.
The girl attempts to join but because she was too young, they kicked her out. She's desperate to express herself the way she wants to and tries her hardest to join. She'll do anything she can.