THE iDOLM@STER Cinderella Girls (2015) : 1x23

With the fall fest finished, the Cinderella Project members have ascended another stair. But when Uzuki suffers a crisis of confidence, she tells Producer that she wants to go back to the basics and subsequently returns to training school. Feeling that something is off, Producer frequently visits Uzuki at the school to keep an eye on her, but she sticks to her usual line of "I'll do my best." Producer doesn't think Uzuki is heading in the right direction, so he sets up a Christmas concert for New Generations and entreats her to re-enter the fold there. However, Uzuki doesn't show any enthusiasm for the plan. When Producer tells Rin and Mio about Uzuki's condition, they become anxious and go to the training school to see how she really feels. They find that Uzuki has lost her former dazzling smile...