Lovedol, or Lovely Idol, is a girl group consisting of two generations of idols. The 3rd Generation is about to make its debut, but to their surprise, they have been delayed! The vague reason is only that "they lack something." The manager, and the 3rd Gen. girls too, must find the answer.

The film's story is set in the Doll Kingdom where dolls reside. Happiness Charge PreCure are asked to help by a women named Tsumugi when the sudden appearance of Saiarks begin wrecking havoc upon the Kingdom. However all is not what it seems with the mysterious man Black Fang dwelling in the shadows.

Coworkers Yui Mitsuya and Masugu Tateishi are the last people anyone would expect to get along—especially with their constant office quarrels. However, looks can be deceiving: they are actually dating! Afraid to lose the peace of their professional lives, Yui and Masugu play up their discord even more to ensure nobody discovers their secret. As awkward situations and close calls pile up, the risk of Yui and Masugu's coworkers catching on increases. Keeping up the pretense is not easy, but with each new day, their relationship only grows stronger.

In order to save a princess, Mantarou (Kid Muscle) and the gang must find a special ginseng. They are later joined by Kevin Mask.