One day, Amane Aika receives a parcel from her older brother, who should be hard at work as an idol.

"I'm going off on a trip now, so could you switch places with me for a bit?"

Along with that letter was a wig and clothing for boys. Aika couldn't read some parts of the letter as it was slightly dirty.

Convinced that something must have happened to her older brother, Aika decides on swapping places with him.

However, what lies in await for her were other idols who were causing various problems...

[Translation of official website story summary.]