Get your groove on with Rockin' Pretty, a music rhythm game starring four teenage girls trying to make it as rock stars. Select one of four instruments, including lead guitar, bass, keyboard, or drums, and then use your stylus to tap or strum on the touch screen in time to the beat. Earn applause and "stars" after each successful performance and move one step closer to fame and fortune. Accumulated stars can also be used to unlock additional clothing options, hairstyles, and instruments for personal use or to trade with others via wireless connection.

Every year, bands gather from all over the country to participate in the "Rockin' Pretty" contest. Those who win are awarded a record deal, several hits, and stardom. Mai watches a DVD of Rockin' Pretty in the lobby of Rockin' Hits Studio. She has always wished to enter Rockin' Pretty but has never found a band to join. However, Ken introduces her to his sister Kara, who is in dire need of a new guitarist after recently losing her old one. The group performs "See you again", which went better than expected. After their performance, the band accepts Mai into their group. They head to Central Park shortly after, which is known for hosting many band performances. "Starlight" performs attracting a number of people, but is overshadowed by the boy band "The Dreamboats". Fearing that they can't find places to perform, "Starlight" visits Michelle, a former Rockin' Pretty participant, for help. "Starlight" is booked to play in Star Cafe, a famous cafe known for the variety of music played. There is a rumor that if the owner likes a band's music, they'll do well in Rockin' Pretty. Following their performance, DJ H-Star compliments "Starlight" on their performance and reveals that he is the owner of the cafe. He tells them that although they are lacking skill-wise, they have soul. The next day at the preliminaries, DJ H-Star visits "Starlight" to tell them that they are performing first. Out of the twenty bands, the two who made it to the next round were "The Dreamboats" and "Love Connection". However, runners-up have a second chance at the preliminaries at Melody Mall. Thirty bands have arrived at Melody Mall and "Starlight" was selected as the 15th band to perform. During their waiting period, Reena felt that they just didn't reach their crowd's heart. Mio suggests that they should be more cute, energetic, and have more fun. The band accepts Mio's suggestion and decide to play "Fluttering Heart" and "Happy Sunday". Their new style was an apparent success and will be moving on to the semi-finals. The band had decided that they wanted to play one more live show before semi-finals. However, most places are booked so Reena decides to bring them to Symphony Park. They decide to play here and ask Ken to bring the instruments. The park performance was a complete success, attracting a wide variety of people. On the day of the semi-finals, the girls play with confidence and spirit. At the end of the semi-finals, DJ H-Star announces that "The Dreamboats" and "Starlight" will make it to the finals. He also compliments the girls on their improvement since the preliminaries. On the day of the finals, the girls reminisce on how they met. Following the performance of "The Dreamboats", the girls thank everybody who has helped them and promises to make this their best performance, playing the song "Rockin' Nova".