After giving a group performance, Yume, Rola, Mahiru, and Ako are given a three day break from their activities. Learning that Yume's family runs a well known bakery, the girls all go to Yume's house to try their pastries.

The girls star in yet another drama, titled Aikatsu Detectives! The Princess Diamond Incident. As phantom thieves known as the Shadow Stars plot to steal Hime's Princess Diamond, Ako joins Tsubasa, Yuzu, Yozora, and Mahiru as part of an investigation team guarding the diamond at a party.