D4DJ: First Mix

Rinku Aimoto is taken by the school broadcaster, Maho Akashi, to a performance by the DJ group Peaky P-Key, which inspires her to form her own DJ group.

Rinku learns about song transitions from Maho, and the two of them put up a promotional poster; Maho enters a remix contest.

Muni Ohnaruto realises that Rinku is her childhood friend, but is hesitant to talk to her; however, when she comes across Rinku and Maho discussing flyer designs, she can't keep herself from butting in.

The members of Happy Around! decide to write a song for Photon Maiden's songwriting competition.

Muni wants to increase her popularity by singing an image song and invites Rei over to her house to help her compose one.

Happy Around! is fully formed at last, but final exams threaten to get in the way of their DJ activities.

Happy Around! is preparing to hold a Christmas Event, but are unable to book a concert hall on Christmas Eve; Rinku is deeply shocked.

Maho is afraid that Rinku is being recruited to join Peaky P-Key, and schedules a meeting with their DJ Shinobu.

After Happy Around! and Photon Maiden tie for eighth place in the Sunset Stage rankings, they must compete in a one-on-one battle to qualify for the competition.

Photon Maiden wow the audience with their overwhelming performance; using Rinku's idea, Happy Around! follow up with a new song introducing Rei as the main vocal.

New, calmer color in songs by Happy Around!; Photon Maiden's Saki Izumo enters the upcoming remix contest and catches Maho's attention.

Happy Around! decide to go with Rinku's idea and challenge rap, but Rinku and Muni become estranged after a misunderstanding; seeing Maho and Rei worried, Airi steps in to offer some advice.

Rinku and her fellow Happy Around! members challenge the undisputed champions on Sunset Stage, the stage of their dreams.