D4DJ First Mix

Rinku Aimoto, transfer student to Yoba Academy, meets DJ-in-training Maho Akashi. Seeing that Rinku is interested in DJ activities, Maho takes her to see the performance of the most popular DJ unit in the school, Peaky P-key. Consumed by the excitement of the performance, Rinku asks Maho to form a DJ unit with her.

Having formed a DJ unit with Rinku, Maho decides to host their first school concert. However, they are unable to attract the other students' attention. Looking for a way to change the situation, Maho comes across a school remix contest and decides to apply. She works all night and creates a remix that Rinku also likes, who then joins the contest alongside Maho. And the winner of the remix contest is...?!

Muni Ohnaruto realises that Rinku is her childhood friend, but she is hesitant to talk to her. However, she comes across Rinku and Maho discussing flyer designs, and can't stop herself from meddling in. Rinku rejoices at the reunion and asks Muni, who is a talented illustrator, to be the VJ (Video Jockey) of the group.

Having welcomed Muni to the unit as VJ and gaining popularity through their concerts, Rinku and her friends decide to apply for a song composition contest. Rinku, who has started to practice piano for song making, introduces Teacher Rei-chan to Maho & Muni.

To gain more attention, Muni says she wants to take part in singing as well. Rei begins to compose music themed after Muni, while Rinku suggests to Rei to have a pajama party at Muni’s house to deepen their friendship.

Happy Around! has been formed at last! It seems everything is going smoothly for their DJ activities... but suddenly the final exams stand in Rinku, Muni, and Rei's path. To get them out of this crisis, Maho cooks curry...?!

Happy Around! is preparing to hold a Christmas Event, but they are unable to book a concert hall on Christmas Eve. Rinku is deeply shocked, but Kyoko Yamate from Peaky P-key appears and...

Rinku's guest performance at Peaky P-key's Christmas Concert was well received, and she is very excited about the results. Seeing her joy, Maho becomes anxious and consults Shinobu Inuyose about the thoughts bothering her.

Happy Around! places 8th in the Yoba Academy DJ rankings! However, the famous Photon Maiden has tied with them for 8th place. The two units face off to decide who will perform on the Sunset Stage.

Photon Maiden awes the audience with their overwhelming performance. Happy Around! faces off with a new song which, following Rinku's idea, introduces Rei as the main vocal.

Having seen a new color in Happy Around!'s performance, Saki starts to explore if they too have new colors of their own. Thus, Photon Maiden encounters a light that they have never experienced before.

Happy Around! decides to challenge rap following Rinku's idea, However, Rinku and Muni becomes estranged due to misunderstanding. Seeing Maho and Rei worried, Airi steps in to give them advice.

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