Kanakasa

Kanakasa is the het ship between Kanade Yoisaki and Tsukasa Tenma from the Project SEKAI fandom.

Canon
Kanade and Tsukasa are the leaders of their musical groups, 25-ji, Nightcord de. and Wonderlands x Showtime respectively. They have completely opposite personalities, as Kanade is very soft-spoken and Tsukasa is very loud, to the point where his voice can approximately reach the loudness of a train on an overpass.

Although they are so different, one of the things that "links" them is that they both have an ill relative (Kanade's father and Saki) who caused them to pursue their dream. In Kanade's case, her savior complex developed after her father's collapse and she started composing frantically in hopes of saving other people with her songs. Meanwhile, Tsukasa's ambition of wanting to become a world star in order to make people smile with his shows came from the desire to make Saki smile, although he had initially forgotten about it.

Singing Among the Cherry Blossoms
The two first met in Episode 8, when Tsukasa claims to be late for show practice and bumps into Kanade. The two have some small talk and Tsukasa looks rather calm, until he remembers he's late. He returns to his usual self and apologizes. After he leaves, Kanade thinks his voice was very loud.

At This Festival Colored by Twilight
Tsukasa and his troupmates meet the 25-ji Nightcord de. members, except Mafuyu, and Tsukasa introduces himself being loud as usual. Kanade then comments that he is very loud and that his voice sounded familiar. She then remembers him from their interaction in Singing Among the Cherry Blossoms.

A Brand New Year! Lion Dance Robot's New Year's Show!
The two interact in Chapter 6, in which the members of Wonderlands x Showtime are performing and the Nightcord members are watching them. During an emotional scene there's an audio problem and the background music gets cut off, so Kanade rushes over to the piano and continues the song using her music skills. After the performance Tsukasa thanks her and they properly introduce themselves. Later, in chapter 8, he says that Kanade's part of the melody "pierced his heart straight through".

Fanon
Due to a lack of interactions, in the Western fandom Kanakasa is considered a rarepair. Still, a small part of the fandom seems to like the ship due to Kanade and Tsukasa being leaders, somehow sharing a dream and similar traits (making people smile with his shows/saving people with her music, both are hardworkers to the point where she forgets to eat and he gets sick), and their possible sun/moon dynamic. Some fans found out about the ship thanks to their "Scramble Fan Festival!" cards.

Recently, people started seeing their relationship as a brother-sister one due to Tsukasa's VA saying that he would like to have Kanade as a sister and leading to some people claiming they are "sibling-coded". Some have even gone as far as headcanoning Kanade getting adopted into the Tenma family, while many have voiced their anger over people forgetting that Kanade still has a father. This has also caused people to prefer shipping RuiKasa and Kanamafu.

On AO3 it is the most written het (and the fourth overall) ship written for Kanade, with Tsukasa's being Emukasa. However, in the Eastern fandom the ship is more supported, as there are around 200 novels on Pixiv.

Fandom
FAN FICTION

FAN ART

TWITTER

Trivia

 * Their ship is referred to with the "🎼🌟" emojis.
 * They have a height difference of 18 cm, with Tsukasa being 172 cm and Kanade being 154 cm tall.
 * One of their Cheerful Carnival Team names is "Unfamiliar Faces".