TSUKIMIYA AN

One day, an angel fell from heaven. Along the way, she lost two of her feathers. Now, she is banished from heaven until she can find them, and thus our story begins...

From Wataame Shoujo:The story is about Kobato going to Japan to find her brother but accidentally, she becomes an idol when she met Takeru. The catch is Takeru and probably everyone else actually thought she was a he because of how she acts and dress