SayoHina

Sayohina is the family ship between Sayo Hikawa and Hina Hikawa from the BanG Dream! fandom.

Canon
Hina and Sayo are twin sisters; Sayo is the elder, while Hina is the younger. Hina is a genius who can do things at first try, but easily gets bored of them while Sayo is a hardworker who often spends a lot of time mastering her skills and needs more time to learn. Sayo is serious, stiff and stoic, while in contrast Hina is very bubbly, carefree and optimistic; however due to her genius nature she has trouble understanding peoples' struggles. Both are members of their schools' student councils: Hina is Haneoka Girls' Academy's student council president, while Sayo also doubles as a discipline committee member in Hanasakigawa Girls' Academy.

Ever since the two were young, Hina had always bested Sayo in everything due to her genius nature, from simple things to test scores. As a result Sayo formed a severe inferiority complex towards Hina, and as they got older, Sayo's feeling of inadequacy caused her to drift away from her twin, until eventually she began trying to shut her out of her life entirely.

In Roselia's First Band Story, which tells the story of how Roselia was formed, Hina and Sayo's strained relationship is shown in detail. Sayo dislikes the burden of being Hina's older sister and getting constantly compared to her. She even started playing guitar only because it was something Hina wasn't doing, and because she wanted to beat Hina at something for once. This is also her biggest motive for joining and creating Roselia together with the band's vocalist Yukina.

Their first scene together is shown when Hina invites Sayo to come and watch a TV show about dogs with her and their father, where Sayo reveals Hina doesn't even like dogs, but the latter just wants to spend time with Sayo. This leads to Sayo getting angry, saying how just because they were born on the same day doesn't mean they need to do everything together, and how they promised to not get in each other's hair once they started high school. Hina then apologizes and leaves Sayo's room.

In Chapter 10, Hina talks to Lisa asking whether she'd really joined a band with Sayo, and then reveals that Sayo never tells Hina anything about herself. She then proceeds to ask whether Sayo has fun and looks happy while Roselia is practicing. When Sayo finds out that Hina has joined Pastel*Palettes as their guitarist in Chapter 11, she becomes enraged and ends up blowing off at Roselia due to Ako praising her older sister Tomoe. In Chapter 13, she almost passes out due to practicing too hard at home, which leads to Hina entering her room in worry, and Sayo yelling at her to leave. In Chapter 17, after Roselia broke up due to Yukina hiding her true intentions for creating Roselia, Hina finds Sayo practicing in her room and asks if she's going to quit playing. She then goes to comment how Sayo's playing sounds more individual and not as robotic as it used, which leads to Sayo telling her to leave but in a softer tone. In the final Chapter of their Band Story, one of Hina's fans approaches Sayo while they're at the family restaurant, asking if she's related Hina. Sayo answers "yes" and after the girls leave, thinks how she'll most likely never be able to escape Hina's shadow.

In the third chapter of the event "Past Aspirations and Pastel Futures", after Hina and her band members talk about their aspirations and why they got into music, Hina tells Sayo that she is the reason why Hina started playing the guitar. She talks about how being in the band has made her more aware of people and understanding the importance of teamwork, and it's all thanks to Sayo; after that, Sayo says that while it was very stressful that Hina quickly exceeded her, but it also motivated to push her harder and join Roselia, which is something Sayo is also thankful for. The two then make a promise that neither will stop playing the guitar, and if they do, they'll never forgive each other.

Their first major event together (outside of their respective band stories) in the game is "Wish Upon a Tanzaku". Hina wants to invite Sayo to the Tanabata Festival, but the latter is not warming up to the idea as she dislikes big crowds and festivals. Hina then goes to the festival all by herself, and while writing her tanzaku, she ends up running to Sayo who was running an errand for their parents. The two stand around awkwardly before a bird steals Hina's tanzaku and they start chasing after it. They arrive at a park which the two used to frequently go to when they were younger, and find Hina's tanzaku from the ground while reminiscing old times. Sayo also learns that Hina is part of Haneoka's Astronomy Club, which is also called the "Weirdos Club". After a while the twins return downtown where they spend time together, and Sayo writes a tanzaku as well wishing "they could be open and honest with each other", while thinking it'll eventually happen. Hina also reveals that her wish on her tanzaku was "having a fun day together with Sis".

The second, and most popular event between them, is the "Umbrella For The Autumn Rain" event which begins with Sayo seeing Hina perform on TV, leading to her compare their sounds and wonder if hers is lifeless and dull, despite being a precise player, and Hina constantly complimenting how much better her playing started sounding earlier in the story. This leads to Sayo falling into a slump, performing badly during Roselia's practices, comparing herself to the other band members and eventually refusing to play the guitar. After talking with Yukina, and Ako's older sister Tomoe, she realizes she needs to face Hina head-first and talk to her about her complex. Sayo ends up skipping Roselia's practice that day, and it suddenly starts raining heavily. Hina barges into Roselia's practice wanting to bring an umbrella for Sayo, but ends up finding that Sayo has gone somewhere else. The two then meet downtown, and Sayo ends up breaking down due to realizing how she always keeps rejecting and pushing Hina away, yet Hina still keeps coming back to her.

When the two get home, Sayo apologizes for crying and then decides to confront Hina about everything. During their confrontation Sayo explains her inferiority complex towards Hina, how she loathes herself for not being able to make the wish on her tanzaku come true, and how her playing is truly dull. Hina gets mad at Sayo saying she'll quit the guitar, and reminds Sayo that she is the reason why Hina started playing guitar in the first place; how she doesn't care if Sayo ends up hating her more, as long as she keeps playing. This causes Sayo to snap out of her state and tell Hina how she wishes to be able to walk by her side one day and feel pride in the sound she makes. The event's main song Determination Symphony's lyrics also talks about their relationship.

Their third event together is "Twin Star Ensemble", in which Hina finds out that her Astronomy Club is going to be disbanded unless she provides tangible proof her club is doing its activities properly. She asks Sayo for help, and despite reprimanding her, decides to help Hina out with planning a stargazing event. Sayo goes and lends out astronomical books from Hanasakigawa's student library and tries reading the club's journals in order to understand what Hina finds so fascinating about them. Hina later shares a story to Lisa, Kokoro and Tsugumi how Sayo has always been a serious and sweet older sister to the point where Hina made her cry thinking about a reason for why animals could talk in a book they were reading together. Their stargazing event ends up being successful and Sayo says that it's fine they don't think the same way about everything and how everyone should be brilliant in their own way, similarly to the Gemini constellation.

In the "We're All Here! New Year's Party!!" event, in which all of the 25 girls assemble at CiRCLE for the New Year's party, Hina signed her and Sayo up for the party's talent contest without the latter's knowledge, though she accepts the challenge. In their part they pull off two tablecloths off the table without breaking anything, where Hina also reveals they used to do it often when they were younger. After they successfully pull the trick off, Kasumi and Aya comment how in sync they are.

In BanG Dream! 2nd Season, Hina confronts Sayo and Rinko Shirokane, Sayo's fellow bandmate and their school's student council president, about holding a joint cultural festival. In the 9th episode, "School Festival Symphony", where the girls perform in order to buy time for Poppin'Party's cultural festival performance, Hina offers Sayo her guitar which she uses to play Determination Symphony with.

Hina is also very affectionate and often says she loves Sayo, which tends to embarrass and make the latter blush. Hina has also expressed envy for her bandmate Aya for attending the same school as Sayo. In one of the Lounge conversations between Tsugumi and Hina, Hina is talking about what she and Sayo had done together. Tsugumi then giggles and says that Hina truly likes Sayo, which the latter confirms, and then proceeds to say that she loves Sayo. Adding to this, in one of their Live interactions, Hina yells "I love you, Sis! ("Onee-chan, daiiisuki!" in Japanese)".

Fanon
Sayohina has a very mixed reception in the fandom.

In the Eastern side of the fandom, it is the most popular ship, has the most fanart and fanfictions and even had a doujin event (which was held on March 21, 2019) solely dedicated to the ship and both girls separately. Most of the fanart is romantic or angsty in nature. Though some people shipped them before any major events, the ship's popularity raised through the roof with the Umbrella For The Autumn Rain event, which deepened their complex relationship.

In the Western side of the fandom, people who support it romantically are in the minority. While there are people who support it platonically and expressed their love for their sibling relationship, the ship itself is heavily disliked and controversial due to their blood relation. In fact many people have even gone as far sent death threats to people who ship Sayohina romantically, tried getting players who shipped it openly banned from the game and ignored its prevalence in the Eastern side of the fandom. The ship is also disliked by many people who either ship Ayahina and Sayotsugu or both.

The hate for the ship in the Western side of the fandom culminated when an user named "tsuugusayo" started spamming the comment sections for most, if not all Sayohina fanfics in AO3 with lyrics of certain BanG Dream! songs in August 2020. They even went as far spamming 10 fanfictions in the same tag, with all of the fics being filled with nothing but death threats and insults, and name-calling everyone who expressed concern over their obsessive nature in the comment sections.

Fandom
FAN FICTION

Trivia

 * Sayo is 161 cm tall, while Hina is 156 cm.
 * The girls' names are parallel to each other; the "Yo" in Sayo's name means "Night", while the "Hi" in Hina's name means "Day".
 * Both of them love trash food (despite Sayo stubbornly denying it).
 * Hina and Sayo's voice actresses, Ari Ozawa and Haruka Kudou, have also shown support for the ship multiple times. Haruka even quote-tweeted a tweet talking about a BanG Dream! 3rd Season pre-release event with one of the Japanese tags for the ship.
 * In BanG Dream! Girls Band Party!☆PICO Episode 24, which is titled "Twin Rhythm", it is shown that the two share some kind of telepathic connection.
 * Hina is the only person Sayo refers to with her first name and without honorifics.
 * In the Pastel*Palettes! Deserted Island Idols event, where Hina and her band members go into a deserted island in order to film a TV special, each of the members was allowed to bring one item with them. Hina bought a picture of Sayo with her, saying that she can sleep like a baby while around it.
 * In one of Hina's 2019 Birthday lounge conversations, Sayo gives her a present which happens to be a pendant with the Gemini constellation on it. Lisa, who is also there with them, says Sayo spent a lot of time looking for it, which in turn makes Sayo blush and tell Lisa to not "say anything unnecessary". In another, the other members of Pastel*Palettes give Hina tickets to the planetarium as a present, and Chisato suggests that she should invite Sayo to go with her.
 * In one of the lounge conversations between Sayo and Kokoro (titled "Stargazing"), Kokoro mentions that she had gone stargazing with Hina the other day. Right after Kokoro says that Hina talked about nothing but Sayo throughout their trip, which causes Sayo to blush and stutter.
 * Hina mentions Sayo in two of her autumn dialogues. In one of them, she says she'll buy enough of the limited autumn-flavored french fries to share with her, while in the second, she tells herself to remember and tell Sayo about how beautiful the autumn moon looks.
 * In a New Year's map conversation, Hina is crying over the fact that Sayo didn't send her a New Year's card, which just makes Sayo shrug it off with a "we live in the same house, so why should I?"