Nagisaori

 is the femslash ship between Nagisa Tsukimiyama and Saori Hidaka from the D4DJ fandom.

Canon
Saori and Nagisa are both sophomores at Seiho University as well as members of their respective DJ units, Merm4id and Rondo. Saori serves as Merm4id's DJ, while Nagisa is Rondo's guitarist. The two of them used to be classmates in high school, however they didn't keep in touch after graduating. Nagisa is energetic, airheaded and touchy, while Saori is calmer and a bit more shier. They were first shown interacting in the first chapter of D4DJ: Groovy Mix's third event story.

Merm4id and Rondo end up having their live shows on the same day and in the same club, and as Merm4id is entering the club, Saori immediately ends up running into Nagisa. Both of them are surprised, before Nagisa asks Saori how she's been doing and mentions that they haven't seen each other since graduating from high school. Hiiro, Rondo's VJ, also remarks how wonderful it is that the two have now reunited. After performing, the two units discuss their shows in the club's backroom which leads to Marika, another member of Merm4id suggest they do something together. Rika, Merm4id's leader and main singer, then suggests they go to a resort hotel together and let them leave the planning to her. In the second chapter, Rika's mistake leads them to going into a ryokan inn with multiple kinds of baths instead of a resort hotel. Although Saori starts apologizing for Rika's mistake, Nagisa says that it's not a big deal because the place seems cool.

In the third chapter, Nagisa and Saori sit around in one of the baths together. Saori instantly mentions how she was worried how things would end due to Rika's usual nature, which Nagisa counters by saying Saori hasn't changed at all and how she's still a worrywart. Her comment causes Saori to deny it, but Nagisa says it's not a bad thing. Nagisa then proceeds to reminiscence about their time together during one of their school festivals as well as highlighting Saori's hardworking nature. During the school festival's musical performance, Saori had been worried about the equipment so she spent extra time and slightly delayed the beginning just to ensure that the performance would go perfectly.

Saori gets embarrassed upon hearing that Nagisa saw her back then, which leads to Nagisa complimenting and calling Saori cool. Saori claims that she doesn't like half-assing things so that's why she worked so hard, but also mentions regretting that time because she bothered everyone. Nagisa denies her claim again, saying that the performance ended up being even more exciting and cooler, beyond what a normal high school production would be like thanks to Saori's hard work and effort, which lead to Nagisa playing the guitar even better than she'd expected and her becoming popular in school after that. Saori mentions that she was amazed by Nagisa's easygoing attitude, while Nagisa says that the reason why they got along so well was because Saori was a humble girl. The chapter ends with Nagisa telling Saori that her outlook has changed since she joined Merm4id, and that she wants to know more about her unit.

Nagisa is also the 3* gacha card for the event. In its card story (titled "Even Brighter, You Shine"), Saori is first shown fidgeting around and being nervous before Nagisa approaches her, after which Saori says that she's not used to bathing together with her friends. Nagisa tells her to stop worrying and how they shouldn't waste any more so she invites Saori to enjoy the bath with her. Saori agrees but ends up slipping and Nagisa catches her, before teasing her about the way she moved and asking if she's the kind of DJ who'd dive into the crowd during the performance. Nagisa then asks if she can sit next to her, before mentioning that Saori has truly changed because she was way more reserved in high school, and how surprised she was upon learning that Saori had even joined a DJ unit. Saori responds by saying that she couldn't imagine herself doing that either, as she is not as confident when it comes to her musical skills, at least compared to Nagisa, and then tells about her meeting with Rika that also lead to the events of Saori joining and creating Merm4id together with her. In turn, she asks Nagisa for her reason on joining Rondo, before saying in surprise that she had expected that Nagisa would rather play all by herself and being the center of the attention, instead of joining an unit. Nagisa agrees but also says that performing together with everyone made her realize just how fun it is, and how she shouldn't throw away the chance to do something as exciting and fun as that. The two end up complimenting each other, which causes Saori to get embarrassed, and Nagisa ends the story by saying that she loved seeing how cool Saori was onstage while DJing and wishes she'd show her another hype performance soon.

Fanon
Nagisaori is a huge rare pair in both the Eastern and Western fandoms. On top of the D4DJ franchise not being that well-known, Nagisaori itself is also shipped a lot less compared to Nagisa's other ships, especially Nagihiiro, considered the most intuitive and popular due to her great interaction with Hiiro in the plot. The ship itself does not even have a Japanese ship tag yet, nor even any fanfiction in AO3 or similar sites.

Trivia

 * Both Nagisa and Saori had prior musical experience and knowledge before they joined their respective units. Nagisa comes from a music-loving family and has played the guitar for a long time, while Saori started DJing in high school, but did not do it more actively because of her pessimistic nature.
 * In an area conversation between the two, Nagisa mentions remembering that Saori is skilled at playing and beating retro games.