岛村卯月是个梦想着偶像而在养成所学习的普通女孩子。某天，346 Production的制作人来到卯月的面前，并告诉卯月她作为灰姑娘计划再次选拔的三个名额之一合格了。卯月非常高兴，但要让计划开始尚还缺少两个人……。制作人打算选拔另一名偶像候补涩谷凛，但凛对于偶像完全不感兴趣而拒绝了……。

卯月和凛第一次来到346 Production。随着与最后的再选拔成员本田未央以及个性丰富的成员们的初次面对面，企划终于开始了。第一项工作是拍摄宣传照片，但她们由于紧张而变得表情僵硬。总算完成摄影的三人，被偶然在场的城崎美嘉指名，突然间就被要求参加伴舞……！？

卯月、凛、未央被美嘉指名而参加了伴舞课程。尽管经历了一番苦战，她们在企划成员的支持下总算迎来了正式演出。但她们却面临着没能顺利地进行彩排就直接面对正式演出的状况……！

卯月、凛、未央参加了灰姑娘企划宣传影片的拍摄。她们拿着相机来回对成员们进行拍摄，但个性各异的成员们却很难搞定……。摄影结束后，制作人向成员们宣告了重大发表！

卯月、凛、未央三人以及美波、安娜史塔西亚两人分别决定以组合出道。她们开始了为了宣传迷你演出而进行的课程，展开了繁忙的活动。但是，想要快点出道的未来心中累积的不满终于爆发了。

卯月、凛、未央的组合定名为“new generations”，美波和安娜史塔西亚则是“LOVE LAIKA”，出道CD的迷你演唱会也决定了。两个组合准备着取材和服装搭配，以出道为目标向前奋进。初次登上舞台的LOVE LAIKA心中充满不安……不论什么事两个人都齐心协力积累了练习。new generations也一直等着和美嘉那时一样的舞台，心中充满期待。之后，终于到了出道演唱会当天。登上舞台的组合所见到的是……？

制作人没能追回飞奔而去的未央。制作人的态度以及独自一人想方设法的样子让凛和企划成员产生了不信任感。之后连凛都离开了企划，企划成员的心开始四分五裂……。当制作人前去拜访不幸感冒的卯月时，看到一心梦想成为偶像的卯月的笑容，于是下定决心要将未央和凛带回来。另一方面，其他企划成员得知了制作人因过去的某个事件导致与偶像的交流变得胆怯的事实……。

时已入夏，制作人与偶像的距离也确实地缩短了，整个企划的气氛良好。而这一次兰子将以独唱CD出道！但兰子所想象的形象与制作人所看到的兰子的形象有很大的差异……。制作人希望理解兰子，兰子则希望将自己的形象传达给制作人而努力，但——。

加奈子、智绘里和杏决定以组合“CANDY ISLAND”出道。但是明言不想工作的杏、我行我素的加奈子、胆怯到连面对客人都感到紧张而无法直视的智绘里，组合充满了各种各样的问题……。这样的三人还是在川岛瑞树、十时爱梨主持的综艺节目中出演了。对客人的观看以及与其他偶像的对决都畏缩不前，三人的团队合作四分五裂。不止如此，残酷的惩罚游戏也公布了出来……！

决定以“凸ration”名义出道的莉嘉、米莉亚、琪拉莉三人与时尚品牌“PIKA PIKA POP”展开合作。她们参与了访谈活动，气势空前高涨，但制作人感觉如果是凸ration的话应该能更加带动观众的……。三人思考着能将观众带动起来的点子，为了稍事休息而前往原宿的街道。但她们却和一同前来的制作人走散了，结果演变成互相寻找对方的事态……！而且下一场活动的时间也迫在眉睫，不要说是带动观众了，就连能不能赶上都是个问题……！

前川未来和多田李衣菜作为灰姑娘企划中最后的组合出道。但以可爱的猫角色偶像为目标的未来以及以炫酷摇滚风偶像为目标的李衣菜，方向性不同的两人对于组合的目标也大相径庭。想着要让组合在Summer Fes中出场的两人打算尽力去做，于是她们开始在未来的房间共同生活……。

决定参加Summer Fes的企划成员在合宿地点进行着课程。此时，为了代替因工作而暂时离开合宿地点的制作人，美波成为了领导大家的人。在组合曲以外又追加了新的全体曲，成员们开始进行编舞的练习，但却无法整齐一致而陷入苦战……。看到这副样子的美波，突然中断了课程……并且提出要举办名为特别节目的运动会……！？

夏Fes终于要正式迎来了。成员们对于企划全员参加的大舞台感到紧张，不过以美波为中心，大家顺利地进行了排练。此时，美波由于极度的紧张状态而倒下。LOVE LAIKA急忙让兰子加入来代替，总算是让灰姑娘企划的舞台能继续进行，然而在突如其来的豪雨袭击之下，演唱会中断了……！

偶像Fes之后一个月，346 Production灰姑娘计划的偶像们一步一步地拓展着活动而成长着。就在一帆风顺之时，出现了暗中接近制作人的诡异人影……！难道说是制作人的跟踪狂吗！？偶像们开始在工作空闲时轮番护卫制作人……！之后，从海外的346 Production关联公司而来，担任偶像事业部门统括重任的女性·美城常务打出了新的方针……！？

美城常务所提出的方针是“将所有的计划解体，变回一张白纸”以及“将选拔偶像以单一计划的形式作出大的成果”。这一方针与制作人及灰姑娘计划和其他部门的体制都大为不同……。偶像们对于被驱逐出至今为止使用的事务所、移动到别的房间感到更加不安。制作人为了防止部门解体以及提出改变常务企划的企划而煞费苦心，但……。另一方面，346Production的看板偶像，高垣枫被美城常务叫了出去……！？

制作人给美城常务提出的企划是“灰姑娘舞会-power of smile-”。这是以发挥偶像们的个性为主体的复合型活动企划。这应该是和美城常务的思考从完全不同的方向对立的企划，但企划的许可被下达了，并且在期限内拿出成果的话即可防止部门的解体。偶像们感到非常高兴，但其他部门，特别是富于个性的偶像们不得不变更活动方针。以兔兔星人的形象保持强烈角色个性的安部菜菜也是其中一人……！同为猫角色的偶像未来也无法放置不管，李衣菜也对未来感到担心……。

为了让灰姑娘计划的存续·舞会企划成功，各自的成长和知名度提升是必要的，制作人与偶像们有着这种相同的心情。在其他部门的协助下企划的新节目“TOTOKIRA学园”这一电视综艺节目开始了，凸ration则在节目中常驻出演！另一方面，在美城常务的要求下，从原本的辣妹路线寻求变更的美嘉，考虑到自己的部门以及后辈的立场，即使路线改变也依然努力。这样的美嘉在TOTOKIRA学园中，与对于寻求和自己不同的路线流露出不满的莉嘉发生争吵。另一方面，米莉亚也心怀芥蒂之情……琪拉莉和偶像们对这两人感到担心。这样下去的话，到底能不能让节目成功……！？

After Totokira Academy gets off to a popular start, Candy Island makes a guest appearance on the show. Chieri and Kanako are so nervous that they act stiff, but with Anzu's casual support, they make it through the taping. The staff loves the stark differences between Anzu and Kirari and gives them a new recurring segment, "Anki Ranking." Chieri and Kanako agree to do to a taped interview for that segment, but Anzu worries about them in her own way.

Seeing how hard everyone is working for the upcoming ball, Chieri and Kanako get fired up, but their nervousness prevents their true talent from coming out, and the interview becomes a hard battle...

Miku and Riina are concerned with improving as a unit to get ready for “Cinderella’s Ball,” despite their usual clashes over the direction of the unit. Meanwhile, Riina becomes friends with a rock idol she admires, Natsuki Kimura, whom Executive Director Mishiro has invited to join a new rock-idol unit.

Connecting with Natsuki, who is devoted to rock, makes Riina remember how much she loves it too. Riina is torn over what she wants to do. Miku picks up on the fact that Riina isn’t her usual self and worries about her partner, but decides to wait until she is ready to talk...

Executive Director Mishiro's new project, Project Krone, begins. It consists of idols who are directly handpicked by the executive director herself. Meanwhile, Producer is suddenly informed that the Cinderella Project is going to come under review at 346 Production's fall festival.

The idols are shaken to learn that if their performance at the concert isn't deemed up to snuff, Executive Director Mishiro won't wait until the winter ball but will disband the department immediately. As chaos and confusion spread, Rin and Anastasia are picked for Project Krone!

Anastasia is positive and determined about participating in Project Krone. But then Mio suddenly announces she's going solo. Meanwhile Rin still can't decide whether to take part in Triad Primus. Amidst all these changes, they strive to find their own paths.

Under the circumstances, it seems like all the previous units and projects will be disbanded, which causes the Cinderella Project members no end of anxiety and upset. The idols decide to band together to make the fall fest a success, but can they?

The fall fest held by 346 Production has begun at last. The Cinderella Project idols are each determined in their own way and fired up as they face the concert. Per Producer's decision, New Generations is sitting the concert out, but Mio and Uzuki are on hand as staff to support the others, while Rin performs with Karen and Nao to make their concert debut as Triad Primus.

Meanwhile, Anastasia performs solo for the first time on stage and all the other Cinderella Project idols shine more than ever. On the other hand, it's the first time for the Project Krone idols to be on stage. Their nervousness reaches its peak right as they're about to go on...

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...

Uzuki has lost sight of herself and lost her smile, but Mio and Rin still believe in her, so they wait for Uzuki to come around. In response to her friends' faith, Uzuki visits 346 Pro, but she still has no good answer to the indecision that's inside her. Mio and Rin decide to watch over Uzuki, who remains in doubt even as she takes a lesson at the office. Afterwards, the other members on the scene share their various feelings as colleagues, friends, and idols.

The encounter makes Uzuki think about what she's currently missing. And then it's Christmas Eve. Producer picks Uzuki up and they head over to the concert venue, but stop off at a certain place along the way...

The Cinderella's Ball finally begins, with the Cinderella Project girls encouraged by Producer to smile as they do each of their routines.