Tsukasaki

Tsukasaki is the Family ship between Saki and Tsukasa from the Project SEKAI fandom.

Canon
In the beginning of the main story Wonderlands x Showtime, Tsukasa and Saki are shown watching a show together. Both say that the star on the show is amazing. Tsukasa is happy to see that Saki is smiling after so long. Years later while Tsukasa is in his room, Saki comes in to tell him to not make much of a racket. She then wishes him luck for his job interview.

Tsukasa asks her how’s school, telling her to not overdo herself because she got better. Saki thanks him for asking but says she’s fine, and Tsukasa says that’s good. Saki says that she’s happy for him since he’s getting closer to his dream, also asking him why he wants to be a star. he responds, and soon after Saki leaves the room, telling him to do his best. Later, when Tsukasa is back in his room, Saki walks in reminding him to go to his job-interview, or else he’ll be late.

In Tsukasa’s room, Saki walks in once again and asks him if he’s writing a new play. He responds with yes, and Saki asks when he’s preforming it since she wants to come see. Tsukasa asks her if she’s feeling okay, since she started working in a cafe and joined a club. While she responds with yep, and says she should make sure not to get carried away because she doesn’t want to bother Tsukasa and the others. Though, Tsukasa then does a show for Saki, and she thanks him. Then, they talk about Saki’s toys, and she wish's him luck with his new show, also mentioning when she see’s him working hard she gets energy.

Fanon
Tsukasaki sailed as a result of the two canonically being siblings. Tsukasaki is very unpopular as a het ship. Most people may prefer to ship RuiKasa, Shihosaki or Ichisaki romantically. People like their wholesome dynamic as a familyship. They're also often headcanoned to be adoptive siblings with Touya, due to his unstable home life.

Variations

 * Tenma Family refers to the ship between Toya Aoyagi, Saki and Tsukasa