The Dancing Lady Ninja! Mom's Secret!? (踊るくの一！母さんのヒミツ！？) is the sixteenth episode of Brave Beats. It first aired in Japan on February 14, 2016.
Mother Fuuka overly dotes on her son Hibiki for the passed few days and only recently has he begun to notice. She seemed to know everything about him: What he's thinking even before he could say what was on his mind. Even preparing meals in advance knowing he would want it that evening. This would trouble Hibki since his mother would go out of her way to take care of him even at the expense of embarrassing him in front of his friends, so he eventually snaps and tells her to stop treating him like some small child.
He eventually feels bad about it and confides in Adeline about the situation; which led to her suspicions that Fuuka was a ninja. Of course, Hibiki dismissed this simply for the fact that it was ridiculous and that Adeline was overreacting. But a picture found by Adeline would soon catch his attention and leave Hibiki questioning his mother's identity.
One day, Fuuka steps out of the house with her face completely masked. Completely won over by the idea that Fuuka was a ninja, Adeline and Breakin decide to follow her. The destination she arrives at was none other than White Castle; the site where Hibiki's class had come to on a social studies field trip. Coincidentally, just as she arrives, Mink and Tank had also come in search of a Dance Stone.
They began to terrorize the castle, but due to their usual fumbling, the stone would fall off the rooftop and right in front of Fuuka. She is possessed by the stone known as Tricking, and the newly acrobatic Fuuka goes on a violent rampage desperately trying to find her son. Hibiki immediately transforms into Flash Beat and tries to subdue his mother. However, he is unable to compete with her movements and is completely overpowered.
Instead of trying to forcefully face her, he decides to take the plunge by receiving Fuuka's attack from the front; resulting in a head on collision. Somehow or another he was able to purify her of the dance stone and she returns to her normal self. Hibiki would eventually ask why his mother had come to White Castle, where she replies that she only came to bring him his forgotten lunchbox. She figured since Hibiki felt too embarrassed to be seen with her in public, she'd come in secret to give him his lunch. He would feel bad and eventually apologize and make up with his mother.
Characters are shown in order of appearance. An asterisk (*) near the name means the character have debuted in this episode.