Four months have passed since Aine has begun her Aikatsu! However, in comparison to Mio, her reputation and skills aren't quite there yet. Under Mio's instruction, she even uploads "'tried to do' videos" onto AiTube, but the number of views don't increase much. Mio, assessing the situation, seems to have become aware of Aine's greatest talent?

Mio starts getting pumped up for she is trying to design a Best Friends Rare dress for Pure Palette. When Mio reaches a wall in designing, Aine invites Mio on a mystery tour planned by Aine herself. Walking along the lands of the forest, they reach the place known as "Hero's Bridge". And to Aine, this bridge that was a part of her childhood memories means?

The young fortune teller, Sakuya Shirayuri pays a visit to Penguin Café. Sakuya, who is known for her accurate predictions, gives Aine and Mio a reading in regards to their upcoming audition. Understanding the meaning behind the reading, will the two be able to create a big bang?