The first crossover title by Konami & PARTICLE is based on a series of yuri drama albums and an arcade game by Bemani. The three protagonists are hard-working Reiana, girly girl Mimi, and tomboy Nyami, who take a journey to another world. This story focuses on their adventures in the Lily Lyrical Cycle world, although the three main heroines from "Lily Lyrical Cycle Rainbow Stage!!!" and the other 12 girls from the Lily Lyrical Cycle drama albums will also show up, sometimes with surprising relationships and pairing. Instead of a single narrator in the story, the player can switch the viewpoint among the narrators, who describe the character's viewpoint.

There is also a rhythm game, where the player asssembles a unit of three main characters, consisting of one of the protagonists or one of the girls of Lilycle, whose center effect is applied to the unit, and four other members. The unit also consists of ten back members automatically selected by the game based on their statistics points and a guest idol belonging to another player, who is chosen by the player. Like other rhythm games, the player plays the Live mode as he or she listens to a selected song. Each song is assigned one of four categories: Ruby, Sapphire, Emerald, Topaz, Garnet, Amethyst, Onyx, Peridot, Alexandrite, and Diamond; the song's category affects the appeal values of all the characters belonging to all categories. During a song, a predetermined sequence of Rhythm Icons scroll from top to bottom towards the target icons in one of five lanes, and the player will tap the target icons as the Rhythm Icons pass over them. In addition, the sequence may also include notes that are continuously held down or flicked in one direction. The player is scored by the timing accuracy of these taps and is given one of five ratings: Awesome, Cool, Fine, OK, Almost. Although the score is not deducted if the player fails to hit a note, the idol unit's life bar decreases whenever the player misses a note. If the life bar goes down to zero, the song will end early. Scoring is also affected by each idol's skill, which provides different gameplay benefits and are activated automatically at random. The complexity of the song's sequence varies based on the player's selected difficulty for the song as well as its level; there are difficulty levels: Novice, Regular, Advanced, Expert, Master, and Pro from the easiest to the hardest. One of the two additional difficulty levels, Pro+, is available at all events of the game, while the other one, Unlimited, is available for certain songs during special game events. Players are restricted from the number of songs they can play at one time by a stamina gauge, which depletes each time the player plays a song and replenishes over time, when stamina drink items are used, or when unpaid items called Star Gems are used. At the end of each song, a result screen is displayed to player, and his or her performance is rated with a letter grade, a numerical score, and a percentage that represents his or her accuracy.

In the side stories, additional sequences that focus on the characters called star communications are made available to the player.