Upon returning to Japan, first-year high school student Rinku Aimoto enrolls at Yoba Girls' Academy and meets Maho Akashi, the school's broadcaster and DJ. Rinku soon develops an interest in DJing after watching a performance by Yoba's famous DJ unit "Peaky P-key", and she and Maho form a group of their own called "Happy Around!". They are later joined by Muni Ohnaruto, a talented illustrator, and Rei Togetsu, a pianist.

The latest idol-themed DJ unit from Yoba Academy. The name comes from Rinku's catchphrase, which she habitually says whenever she is joyfully spinning around. Their primary music genre style is a combination of J-pop and dubstep. They also use happy hardcore and gabber.

Rinku Aimoto (愛本 りんく, Aimoto Rinku)

Voiced by: Yūka Nishio^[3] (Japanese); Emi Lo^[4] (English)

Having lived in Africa as a child due to her parents' work, Rinku finally returned to Japan prior to starting high school and currently lives with her grandparents. On her first day of school, Maho introduced her to DJ activities by inviting her to a performance by Peaky P-key. She was then inspired to create her own DJ unit alongside Maho. An optimist who can be an oddball at times, she can sense how certain musical pieces can connect by moving her body, so she serves as Happy Around!'s lead singer and dancer. Later, she deeply values her friendship with Muni, to the point she can even cry when her relationship with Muni strained. Her name is a play on the word "link".

Maho Akashi (明石 真秀, Akashi Maho)

Voiced by: Karin Kagami^[3][5] (Japanese and English)

A school DJ broadcaster under the name "Mash", Maho started her DJ activity after watching an outdoor concert when she was a little girl. She initially attempted to reject Rinku's DJ unit invitation until she realized how seriously Rinku is about it. She is skilled at cooking and doing housework because she has younger siblings.

Muni Ohnaruto (大鳴門 むに, Ōnaruto Muni)

Voiced by: Haruka Mimura^[3] (Japanese); Lily Ki^[4] (English)

An illustrator and VJ under the name "VJ Only", Muni has been attracting attention on the internet thanks to her drawings. She takes her art seriously, even though she does not accept criticism kindly. She is Rinku's childhood friend, and reluctantly decides to join her unit upon being invited, but almost pulls out from her maiden appearance due to stage fright. Muni wears a rabbit-ear headband on her head and carries a cat plush called Nyochio during performances and in school.

Rei Togetsu (渡月 麗, Togetsu Rei)

Voiced by: Kanon Shizaki^[3] (2019–2022), Maiko Irie^[6] (2022–present) (Japanese); Anairis Quiñones^[4] (English)

Being born to a wealthy family, Rei had lessons in all sorts of activities and she is gifted to the piano. However, her parents set strict expectations that she wishes to be freed from. She serves as the group's composer and arranger. It is implied that in the past, she also attended a similar outdoor DJ concert like Maho, though the two did not know each other at the time.

A popular hip hop-themed DJ unit in Yoba Academy. It was formed during their middle school years. Also known as Peaky, their music style is a combination of techno, hip hop, and electro-pop.

Kyoko Yamate (山手 響子, Yamate Kyōko)

Voiced by: Aimi^[3] (Japanese); Christie Cate^[4] (English)

Kyoko is the charismatic leader of Peaky P-key. Born in a musical family, she has a natural talent for music. She later develops an admiration for Happy Around! after she watched their first show.

Shinobu Inuyose (犬寄 しのぶ, Inuyose Shinobu)

Voiced by: Miyu Takagi^[3] (Japanese); Divi Muse^[4] (English)

A DJ who is the brainy one of Peaky P-key. She and Kyoko have known each other since childhood, though Shinobu constantly rejects Kyoko's requests to form a unit until middle school; since then, they have maintained a close bond together. Besides being a skilled DJ, she also excels in remixing and track-making. On the outside of her DJ activity, she enjoys online gaming.

Yuka Jennifer Sasago (笹子・ジェニファー・由香, Sasago Jenifā Yuka)

Voiced by: Moeka Koizumi^[3] (Japanese); Brianna Knickerbocker^[4] (English)

Yuka is the moodmaker of Peaky P-key. She met Kyoko as she was searching for the "greatest moment" to capture with her camera and decided to join the unit as a VJ. Raised by parents who work as gym trainers, she is very cheerful and kind to everyone, and loves to cheer up her fellow group members whom she regards as her best friends.

Esora Shimizu (清水 絵空, Shimizu Esora)

Voiced by: Reo Kurachi^[3] (Japanese); Kayli Mills^[4] (English)

The self-proclaimed "lovely-type" member of Peaky P-key. As a natural-born entertainer, she joined the unit to bring entertainment to anyone, and is even willing to expend her own fortune to achieve her goals. She is skilled at getting people to let their guards down and speak their minds. Esora is also a childhood friend of Lyrical Lily member Kurumi.

A sci-fi-themed DJ unit working under an entertainment agency and consisting of students at Yoba. Their music style is a combination of trance, techno, and dance music.

Saki Izumo (出雲 咲姫, Izumo Saki)

Voiced by: Risa Tsumugi^[3] (Japanese); Deneen Melody^[7] (English)

Saki is a talented girl who excels in studies and sports. Due to having "synesthesia", she can see color in music. Despite her outstanding skills, Saki's personality looks like a doll, rarely showing emotion unless she is on the stage.

Ibuki Niijima (新島 衣舞紀, Nījima Ibuki)

Voiced by: Ami Maeshima^[3] (2019–2022), Kanon Nanaki^[8] (2022–present) (Japanese); Heather Gonzalez^[7] (English)

The athletic leader of Photon Maiden, Ibuki has participated in many sports since childhood. In junior high, she became hooked on the joyfulness of dancing and singing and started to attend a show production school.

Towa Hanamaki (花巻 乙和, Hanamaki Towa)

Voiced by: Haruki Iwata^[3] (Japanese); Brittany Lauda^[7] (English)

Towa attends the local festivals due to her family's participation in the local youth organization. As a huge idol enthusiast, she still goes to idol concerts and tries to learn from their performances. She loves sweets, but is often scolded by Ibuki for wanting to eat high-calorie foods before performances.

Noa Fukushima (福島 ノア, Fukushima Noa)

Voiced by: Hinata Satō^[3] (Japanese); Michelle Marie^[7] (English)

Noa became interested in theater thanks to her love of literature, and decided to become a performer when she was praised at a theater workshop. Very curious and knowledgeable, she becomes talkative when it comes to things she is interested in. She also kidnapped Lyrical Lily in an episode of Petit Mix, and also has an unhealthy obsession with Muni.

A glamorous tropical-themed DJ unit formed by first-year students at Seiho University, who aspire to become famous like Photon Maiden. Their music genre consists of electro house and progressive trance.

Rika Seto (瀬戸 リカ, Seto Rika)

Voiced by: Natsumi Hirajima,^[3] Ayasa Itō (young) (Japanese); Kira Buckland^[7] (English)

Holding "Life is to enjoy!" as her motto, Rika leads a positive university life. She loves to dance and sing with her friends at parties. She started her DJ activities with her best friend Marika along with Saori and Dalia whom she met by chance.

Marika Mizushima (水島 茉莉花, Mizushima Marika)

Voiced by: Mei Okada^[3] (Japanese); Kelly Baskin^[7] (English)

Marika is an easygoing person who likes to comfort. Besides being a university student, she also works as a model. She was the center of attention upon entering university, but she became friends with Rika, who was able to talk to her despite all the attention.

Saori Hidaka (日高 さおり, Hidaka Saori)

Voiced by: Himari Hazuki^[3] (2019–2025), Iroha Sakurada^[9] (2025–present) (Japanese); Jackie Lastra^[7] (English)

Saori started her DJ career in high school, and due to her hard-working nature, she has built up a certain level of technique. Her negative thinking held her back from DJing actively, even as a university student. Rika forced her to join the unit, but has made up her mind to change her mentality and achieve her goals.

Dalia Matsuyama (松山 ダリア, Matsuyama Daria)

Voiced by: Ai Negishi^[3] (Japanese); Lauren Landa^[7] (English)

Dalia devotes herself to practicing ballet, traditional Japanese dance, contemporary dance, and any other form in order to become a dancer. Also, she acts as the bodyguard of the unit.

A gothic rock-themed group consisting of first-year Seiho University students who work at a famous club called "ALTER-EGO". Their music style is mainly a combination of trance and rock with touch of drum and bass.

Tsubaki Aoyagi (青柳 椿, Aoyagi Tsubaki)

Voiced by: Rihona Kato,^[3] Mikoi Sasaki (young) (Japanese); Madeline Dorroh^[7] (English)

A born vocalist who has been humming melodies for as long as she can remember. Tsubaki was asked to join the DJ unit, which was lacking a vocalist, by Aoi, and quickly attracted attention as soon as she joined. It is implied to varying degrees that she developed a crush on Aoi due to her handsome looks and prince-like personality.

Nagisa Tsukimiyama (月見山 渚, Tsukimiyama Nagisa)

Voiced by: Sae Ōtsuka^[3][10] (2019–2024), Shuri Miyumi ^[11] (2024–present) (Japanese); Lizzie Freeman^[7] (English)

Nagisa is Shinobu's cousin who grew up in a rock music family. She came across the club where Aoi performed as a DJ when she was searching for a place to practice, and often visits Hiiro's house as well.

Hiiro Yano (矢野 緋彩, Yano Hīro)

Voiced by: Haruna Momono^[3] (Japanese); Natalie Hoover^[7] (English)

The most mature member of Rondo. As a VJ, her knowledge in art allows her to build the unique worldview of the unit.

Aoi Miyake (三宅 葵依, Miyake Aoi)

Voiced by: Tsunko^[3] (Japanese); Justine Huxley^[7] (English)

Aoi is a DJ that performs exclusively for a members-only club. She took interest in Tsubaki's singing skill and asked her to form a DJ unit.

A lolita-themed DJ unit from Arisugawa Academy, a prestigious all-girls Catholic school. Their music style is a combination of synth-pop, house, and classical music.

Miyu Sakurada (桜田 美夢, Sakurada Miyu)

Voiced by: Hazuki Tanda^[3]

Miyu is a kind-hearted person with a good conduct. She started her DJ activities when she came across some analog equipment with her friends. She loves singing, and is well-versed in popular songs from the Showa era as well as nostalgic music due to her family's influence.

Haruna Kasuga (春日 春奈, Kasuga Haruna)

Voiced by: Amane Shindō^[3]

Haruna is an earnest girl who belongs to her high school's disciplinary committee. Her soft nature always gets her involved in all sorts of trouble.

Kurumi Shiratori (白鳥 胡桃, Shiratori Kurumi)

Voiced by: Ruka Fukagawa^[3]

Kurumi is Esora's childhood friend. She is a cheerful girl who loves fun stuffs and is bored of attending a strict school for children of rich and prestigious families, Kurumi always looks for the ways to create some kind of mischief.

Miiko Takeshita (竹下 みいこ, Takeshita Miiko)

Voiced by: Yuzuki Watase^[3]

Like Kurumi, Miiko is a cheerful girl who loves to make friends, play and she also loves her fellow members of Lyrical Lily. She has a dream about traveling all over the world and making friends in many different countries, demonstrated by her ability to understand English. However, she is also passionate to the pranks caused by Kurumi and often she helps Kurumi to prank the others, including Haruna.

A former high school DJ unit that disbanded prior to First Mix, due to creative differences.

Airi Amano (天野 愛莉, Amano Airi)

Voiced by: Nana Mizuki^[12] (Japanese); Kelly Baskin^[7] (English)

Airi is a waitress working at the Cafe Vinyl. Eight years prior to the start of the series, she was part of a DJ unit group consisting of herself and three other members. When the four split, she later joined Mana to form Scarlet Canary.

Mana Kase (嘉瀬 茉奈, Kase Mana)

Voiced by: Arisa Komiya^[12]

Mana is a former member of a DJ unit consisting of herself and three other members.

Shano Himegami (姫神 紗乃, Himegami Shano)

Voiced by: Raychell^[12] (Japanese); Lauren Landa^[7] (English)

Shano is a former member of a DJ group consisting of herself and three other members. She is now working as a music producer and is a person who founded Photon Maiden.

Tōka Takao (高尾 灯佳, Takao Tōka)

Voiced by: Hinako Umemura^[12]

Tōka is a former member of a DJ group consisting of herself and three others. She later joins Shano to form Lynx Eyes.

A pop-house DJ unit formed by Michiru Kaibara at the request of Lumina Ichihoshi. Their cosmic aesthetic is relatively close to Photon Maiden's, however, with a lighter and more cheerful style. Although queer or vaguely queer characters have been in the franchise before, this is the first unit to include members who are in an openly lesbian relationship.

Michiru Kaibara (海原 ミチル, Kaibara Michiru)

Voiced by: Kotori Koiwai^[12]

Michiru is an independent DJ player and the childhood friend of Shinobu prior to Shinobu's involvement in Peaky. She aims to best Shinobu and tends to have weird and overreacting expressions. Michiru is later invited to form a unit consisting of herself and three other girls, becoming the DJ for the unit.

Lumina Ichihoshi (一星 ルミナ, Ichihoshi Rumina)

Voiced by: Karin Takahashi^[13]

A popular virtual singer who invites Michiru, Kokoa, and Hayate to form a DJ unit with her. She later reveals herself to be an AI, her data being based off the deceased singer Aria. She is later given a robotic humanoid body to live in.

Kokoa Shinomiya (四ノ宮 心愛, Shinomiya Kokoa)

Voiced by: Akari Yura^[13]

A sharp-tongued first-year honors student at Arisugawa Academy who is invited to form a DJ unit consisting of herself and two other girls. She holds a grudge against Michiru for something she did to her in her past. She is in a romantic relationship with Hayate.

Hayate Tendo (天堂 はやて, Tendo Hayate)

Voiced by: Yuuki Temma^[13]

A poetic first-year student at Arisugawa Academy who has a habit of saying what's on her mind. She is invited to form a DJ unit consisting of herself and two other girls. She is in a romantic relationship with Kokoa.

A gothic-themed American DJ unit backed by Sho Mitsuhashi that will go up against the DJ units of Japan. They are referred only by first name, and their real names or last names are yet to be revealed.

Neo (ネオ)

Voiced by: May'n^[13]

The cool-headed leader and vocalist of Abyssmare. A musical prodigy since she was young, Neo was scouted by Sho to help her achieve her dream to become the world's greatest vocalist. She is the daughter of Aria, a deceased singer whose voice inspired Airi Amano to follow her path.

Sophia (ソフィア, Sofia)

Voiced by: Yūka Aisaka^[13]

The mood-reader and DJ of Abyssmare. She has low self-esteem due to her poor upbringing to the point where she almost committed suicide. She would later develop an unhealthy obsession with Neo after her voice allegedly saved Sophia's life.

Elsie (エルシィ, Erushī)

Voiced by: Tomomi Jiena Sumi^[13]

The dancer and chorus, as well as the self-proclaimed "number 2" of Abyssmare. A cunning and intelligent woman despite her petite stature, she also has a group of bodyguards that wait on her command. She often gets into arguments with Weronika.

Weronika (ヴェロニカ, Veronika)

Voiced by: Misuzu Yamada^[13]

The dancer and subvocal for Abyssmare. In spite of her short temper, she is shown to have a soft spot towards children, especially her younger siblings. She has strong one-sided rivalry with Neo and often gets into arguments with Elsie.

A spin-off unit appearing in D4DJ Groovy Mix. They were first introduced in A Bad Cynic Doggo VOL.1. They mostly perform in Club DOGHOUSE.

Eimi Azai (浅井 詠実, Azai Eimi)

Voiced by: Yurie Igoma^[14]

While her knowledge of music is just barely average, her impertinent and foul-mouthed nature is on another level. She is skilled at stirring up others, her vocabulary consists of wide range of words from academic vocabulary to internet slang, and she is always spouting inappropriate remarks. Due to her subservient personality, Eimi dislikes and has a one-sided inferiority complex towards the sparkling Yoba Academy, and especially Rinku Aimoto.

Bell Bessho (別所 美鈴, Bessho Misuzu)

Voiced by: Saya Aizawa^[14]

Bell's father is the owner of Club Dog House. Having helped out at the club ever since she was young, Bell knows how to handle DJing and sound equipment as well as creating promotional materials and merchandise. She is always smiling, but very strict when it comes to money and expenses.

Shika Shimazu (島津 詩歌, Shimazu Shika)

Voiced by: Konomi Tamura^[14]

A talented musician ever since she was young, Shika gained some recognition as a turntablist. However, as she started fully devoting herself to music, she ended up becoming even more lost and obsessed with all sorts of subcultures. She is a closet fan of Kyoko Yamate.

Date-chan (伊達ちゃん)

Voiced by: Akira Sekine^[14]

An erratic girl whose age and real name are unknown. For some reason, she is the only member who is repeating a grade. For better or worse, she's almighty and proficient when it comes to music - whether it be track making, arranging songs, rapping, and controlling the flow, she can do it all. While she is mostly slow-going, she has a habit of experiencing highs after inhaling sugar.

Ryujin Kofune (小舟 柳人, Kofune Ryujin)

Voiced by: Tōru Furuya^[12] (Japanese); Tony Oliver^[7] (English)

Ryujin is the bartender and owner of Cafe Vinyl. Eight years prior to the start of the series, he was part of the DJ group LM.O., consisting of himself and four other members, including Shinobu's grandfather.

Dennojo Inuyose (犬寄 傳之丞, Inuyose Dennojo)

Voiced by: Naoto Takenaka^[12] (Japanese); D.C. Douglas^[7] (English)

Dennoji is a former DJ and former member of the DJ group LM.O. consisting of himself and four other members. He is also Shinobu's grandfather and served as a big inspiration for her.

Ku Mitsuhashi (三橋 空, Mitsuhashi Kū)

Voiced by: Daigo^[12] (Japanese); Michael Christopher^[7][d] (English)

Ku is the son of Sho Mitsuhashi, a former member of the DJ group LM.O, as well as the first host of the revived D4 FES.

Haruki Kaibara (海原 ハルキ, Kaibara Haruki)

Voiced by: Hisanori Yoshida^[12] (Japanese); Brandon Winckler^[7] (English)

Haruki is a DJ and former member of the DJ group LM.O. consisting of himself and four other members. He is also Michiru's uncle.

Masaki (真咲)

Voiced by: Houko Kuwashima^{Double Mix credits}

Masaki is the general manager of Alter-Ego, the nightclub that RONDO regularly performs at. Her past, as well as her connections to other people, are a mystery to even the members of RONDO.

Laura Bradley (ローラ・ブラッドリー, Rōra Buraddorī)

Voiced by: Shu Uchida

Laura is an English-speaking American DJ maker who befriends Saori on the internet and is the one who offers Saori to make a joint DJ music collaboration.

Sakuya Ennouji (園能寺咲耶, Ennōji Sakuya)

Voiced by: Erika Ishitobi

Sakuya is the student council president of Arisugawa Academy. She has a strict personality and she often places tradition and order above everything, seeing Lyrical Lily's DJ activities as a threat to tradition. She considers Haruna Kasuga to be her rival.

Ayumi Kuon (久遠愛弓, Kuon Ayumi)

Voiced by: Hikaru Akao

Ayumi is the vice president of Arisugawa Academy's student council and a childhood friend of Sakuya. While she has a calm demeanor, she also harbors a manipulative side to her, wanting Sakuya to be dependent on her only.

Hitomi Nakamori (中森瞳, Nakamori Hitomi)

Voiced by: Chiharu

Hitomi is the secretary of Arisugawa Academy's student council. She is a shy girl who once had an interest in DJ-ing.

Riaru Haraguchi (原口莉亞瑠, Haraguchi Riaru)

Voiced by: Rimi Nishimoto

Riaru is the general affairs clerk of Arisugawa Academy's student council. She is talented student with a fixation of "ojou-samas" and their high-class lifestyle. Riaru claims to be descended from a ninja clan.

An anime television series titled D4DJ First Mix was first announced in 2019.^[15] The series was animated by Sanzigen and directed by Seiji Mizushima.^[16] While the first episode had an early debut on October 22, 2020,^[17] the series officially aired from October 30, 2020 to January 29, 2021 on Tokyo MX, BS NTV, and other channels. Happy Around! performed the opening theme "Guru Guru DJ TURN!!" (ぐるぐるDJ TURN!!), while Nana Mizuki and Raychell performed the ending theme, which is a cover of "WOW WAR TONIGHT ~Toki niwa Okose yo Movement~" (WOW WAR TONIGHT～時には起こせよムーヴメント～) by H Jungle with T.^[5][18][19]

Bushiroad announced worldwide streaming,^[20] including in North America, Funimation,^[21] Crunchyroll, and Sentai Filmworks, the latter also releasing the series on Blu-ray in the future, plus Hidive streaming on more parts of the world.^[22][23] Medialink has also licensed the series and streamed it on its Ani-One YouTube channel in South Asia and Southeast Asia.^[24] Aniplus Asia simulcasted the series in Southeast Asia.^[25]

An English dub produced by Bang Zoom! Entertainment began streaming on January 16, 2021.^[5]

D4DJ Petit Mix, a spin-off chibi anime short series, aired from February 5 to July 30, 2021.^[26] Seiya Miyajima directed and oversaw the series' scripts at DMM.futureworks and W-Toon Studio.^[27] The series' theme is "Petit Mix Party Night!" by Happy Around!.^[28]

On March 13, 2022, a special episode titled D4DJ Double Mix was announced.^[29] Seiji Mizushima served as chief director, while Daisuke Suzuki served as director. It premiered on August 19, 2022.^[30]

On April 8, 2022, a second season titled D4DJ All Mix was announced. It features six music groups including Lyrical Lily. The staff reprised their roles with Daisuke Suzuki directing and Seiji Mizushima returning as chief director.^[31] It aired from January 13 to March 31, 2023. Lyrical Lily performed the opening theme "Maihime", while various cast members performed the ending theme "Around and Around".^[32]

A manga adaptation titled D4DJ: The story of Happy Around! was launched in Bushiroad's Monthly Bushiroad magazine on October 8, 2020.^[38]

D4DJ Groovy Mix is a free-to-play mobile rhythm game developed by Donuts and published by Bushiroad for the Android and iOS platforms. A demo version of the game, titled D4DJ Groovy Mix D4U Edition, was released on February 20, 2020.^[47] The full version of the game was released in Japan on October 25, 2020.^[48] An English version was released on May 27, 2021.^[49]

Anime News Network reviewer Christopher Farris considered First Mix "as one of [Bushiroad's] best [idol franchises] so far" and that its animation was quite polished, though saying that it did "not [succeed] particularly well" at implementing the technical DJing elements of the show.^[50] Anime Feminist author Brock K praised the series' explicit representation of a healthy lesbian relationship between Kokoa and Hayate, as well as Tsubaki's crush on Aoi, while also discussing the nuanced approach of the game's storyline and other characters towards Aoi's exploration of her gender presentation.^[51]