Kasuari

KasuAri is the femslash ship between Kasumi Toyama and Arisa Ichigaya from the BanG Dream! fandom.

Canon
Kasumi and Arisa are close friends that often banter. Kasumi teasing Arisa over a little things, and Arisa getting embarrassed from the friendly jabs. Throughout the series, you can see Kasumi consistently hugging and holding hands with Arisa. Even though Kasumi is very touchy with other characters, she is more physical with Arisa then any of the other characters. You can see Kasumi holding onto Arisa many times not only throughout the show, but also in many of either Kasumi's or Arisa's card art.

Their friendship stems from an unusual meeting at Arisa's house, where she finds Kasumi messing around in her grandmother's basement. Arisa, horrified and angered by finding Kasumi snooping around, interrogates her. After Arisa learns Kasumi goes to the same school as her, tries to kick her out, but fails. Kasumi is persistent on taking a closer look at a guitar case she had seen earlier. After looking, Arisa suggests to Kasumi she goes to a live house if she is interested in music. They decide to go together to this live house and see a live performance.

After the performance, Kasumi is convinced that her and Arisa should start a band together. The next day after the concert, Kasumi once again breaks into Arisa's home asking if she would want to make a band together and use her guitar. However, Arisa declines and mentions she is going to sell the guitar online. Eventually, Kasumi does convince Arisa to join her band and they later become very close friends. Kasumi even comes over to Arisa's place for sleepovers, and the like.

Fanon
Since Kasumi is the protagonist of the franchise, and Arisa is her first and best friend among the other characters, this pairing quickly gained the attention of fans, becoming one of the most popular ships in the franchise in record time. The obvious Arisa's tsunderness and the regular running gag about how confused she because of unintentionally too intimate sounding of Kasumi's words only added depth and charm to the duo in the eyes of the shippers.

Kasumi clearly does not have a sense of Arisa's personal space, their interaction subjectively has a lot more intimate moments than other "official" pairings. In particular, this led to the emergence of one of the memes in the first season of the chibi spin-off, where Kasumi jumped so sharply and hugged Arisa that fans began to joke about their kiss.

Also, since Arisa's character song is literally a song about her tsun tsun to Kasumi and describes it as "love", although without explicitly mentioning its romantic or platonic nature, many both among the ship's fans and beyond support headcanon about how minimum one-sided nature of this ship. This is often the subject of heated debate on fandom, as while the franchise producer admitted that he "doesn't like plot complications" and would like to see the franchise as a succinct story about the power of friendship between girls, events continue to create situations where Kasumi unintentionally says or does something ambiguously romantic and it evokes a very strong tsun tsun from Arisa.

Trivia

 * In one scene from their band's story, Tae mistakes the two for having a date during their walk. While Kasumi just clears up the misunderstanding, Arisa gives the full "she isn't my girlfriend!" reaction.
 * Arisa's fandom nickname "Chomama" comes from her character song "Su-Suki Nanka Janai!" (I-I Never Said Love! in English) where she sings the praise multiple times. It is commonly headcanoned as her expressing her feelings for Kasumi in her tsundere manner.

Fandom
FAN FICTION

ART
 * かすあり on Pixiv
 * ありかす on Pixiv