The story is retold to the player by Margaret, and takes place roughly a month after the epilogue of Persona 4 Golden. Since then, Rise Kujikawa has returned to the world of entertainment, and is teaching her friends from Inaba how to dance so they can act as her backup dancers in a live performance at the Love Meets Bonds Festival. Yu Narukami, now living in the city, meets up with Rise and Naoto Shirogane to practice, but they are informed by festival producer Kyoka Uchimizu that Rise's friends will no longer be performing and that Rise will instead be singing alongside her junior idol Kanami Mashita. Kanami arrives shortly thereafter, and they deduce that the change is due to the sudden disappearance of Kanami's idol group "Kanamin Kitchen," whom Ochimizu produces. This reminds Naoto of a recent rumor she had heard, stating "at midnight, if you see a video of a deceased idol playing on the LMB site, you are transported to the 'other side' and will never wake up again." The three view the website to test the rumor, and they are pulled into the world of the "Midnight Stage," a realm in the collective unconsciousness isolated from the TV World, where the Shadows are being bound and controlled by an unknown entity's song under the guise of forming a “bond” with them.

[From Wikipedia]