RuiKasa

"Only you would be bold enough to bring up wanting to try doing something no one's ever done before, Tsukasa-kun. And that's why you're so wonderful!"

- Rui in "Mascot Greeting" first side story

RuiKasa is the slash ship between Rui Kamishiro and Tsukasa Tenma from the Project SEKAI fandom.

Canon
Rui and Tsukasa are third year high school students and members of the theater troupe Wonderlands x Showtime. They are a "well-known duo of weirdos" at their school due to the fact they cause ruckus around the campus daily, which, most of the time, is due to Rui's experiments. As stated in the "The Climax! Kamiyama Cheer Squad!" event, the rest of the student body refers to them as the "oddball one-two," or just the "one-two" for short.

In the current canon, Rui sees Tsukasa not only as a troupemate, but as a close friend he is immensely grateful to. Tsukasa was the first to place unconditional trust in Rui's "crazy" directions and follow them through with all he has, and he's also the reason Rui was able to branch out socially and at school. Tsukasa is noted to be the catalyst of Rui's change by Rui himself during "A Once-In-A-Lifetime Pandemonium?!."

Similarly, Rui also filled a long-empty gap for Tsukasa. He was the first with a director's ability to become so invested in Tsukasa's journey as an actor, and Tsukasa fully trusts in all of the directions and advice Rui gives him, no matter what other people think of them. Additionally, despite all of his complaints about Rui's conduct, he enjoys spending time together with Rui at school, and, during their second year wherein they were in different classes, the two would still often seek each other out outside of class.

Main Story
Tsukasa and Rui first meet during their unit's Main Story. Tsukasa is looking for people to join the newly formed troupe, and he's impressed by the freelance solo performance Rui does at Phoenix Wonderland, before he runs away from the guards for performing without permission. He eventually tracks Rui down to their school's roof, where Rui had been waiting while he watched Tsukasa search the school for him via his drones. After a brief conversation about being each other's fans, Tsukasa asks Rui if he wants to join his troupe, which Rui initially denies but later agrees to after Tsukasa assures him that he will perform any role Rui gives him to "12,000% satisfaction."

The troupe is then fully formed after Rui also invites Nene to join. Throughout the story, it is brought up time and time again that they are a dynamic duo when it comes to performance. Tsukasa is always being pushed to his limits by his director because, according to Rui, "he is an actor worthy of the stage" and can always go the extra mile.

However, on the night of the troupe's first proper performance, the robot Nene uses fails onstage during a scene she's doing with Tsukasa. Rui hurriedly ends the show, and Tsukasa later shouts at Nene, blaming her for ruining the show and expressing frustration over the fact that the audience couldn't experience the performance he wanted to show them. Rui, as Nene's close friend and the one who brought her into the troupe, harshly criticizes Tsukasa for shouting at her for something she couldn't help. He comes to the conclusion that Tsukasa is shallow and doesn't truly care about shows as he, Nene and Emu do, only using them as a vehicle for his own narcissism, and leaves the troupe.

Even after Tsukasa is able to rediscover his true reasoning for loving shows and reconciles with Nene, Rui refuses to return. However, Tsukasa doesn't give up, insisting Rui is an important part of the troupe, and puts on a show for Rui together with Emu and Nene in his SEKAI—the world of his heart—in order to convey their likemindedness, apologize for forgetting something so important, and ask Rui to return. Rui, as someone who never thought anyone would be likeminded and has never had such a grand gesture extended to him, is moved by this, and finally agrees to rejoin.

In the Wonderlands x Showtime Digest (a shorter, animated summary of the unit's Main Story), this scene is fleshed out, adding extra shots of Tsukasa kneeling to Rui at the edge of the stage as they're both lit up by spotlights, and extending his hand for Rui to take.

It's On! Wonder Halloween!
In the "It's On! Wonder Halloween!" event, Tsukasa is injured by one of Rui's robots while rehearsing. Despite the injury not being severe and Tsukasa insisting he's totally fine, Rui is deeply shaken by this, beginning to subconsciously fear abandonment by Tsukasa. As a result, Rui starts to hold back, making his initially "crazy" directions far more tame, which confuses the rest of the troupe.

Tsukasa is the one to voice this confusion as the two later get into an argument over it, frustratedly shouting at Rui for not giving him his usual style of direction, but Rui angrily denies any change. The two leave to cool off, and Tsukasa explains to Emu that the reason he was so frustrated was because he "killed the director's confidence," and that Rui isn't really the one he's angry at at all.

Rui, with the help of Nene and KAITO, is able to recognize that his issue stemmed from fear that the injury would cause Tsukasa to leave, just as the children he used to attempt to direct as a child did whenever he suggested something too dangerous. He's able to reconcile with Tsukasa the day after, both of them apologizing and coming to understand the issues the other was facing.

The event highlights the mutual trust, concern and respect they both have for one another through the lens of Rui trusting Tsukasa to perform excellent feats, being concerned for his wellbeing despite this, and respecting his wishes to continue, as well as Tsukasa trusting Rui with directing the show, being concerned for his mental wellbeing despite this, and respecting his personal boundaries. It is brought up again in "Revival my dream": while Tsukasa does believe Rui's directions are crazy, he also fully trusts that they're safe.

Kamiyama High Festival!
While rehearsing the proposal part of Romeo and Juliet for their play, Rui volunteers to be Tsukasa's partner. Tsukasa plays the part of Romeo, saying "O Juliet! Sun of my life! I beg you, allow me to have your hand in marriage!!" and Rui plays Juliet, responding "Romeo... Then refuse your name and I shall swear my love!". This scene can be seen in KAITO's Secret Guidance card art, with Tsukasa extending a hand up to Rui while down on one knee.

In the same card's side story, Rui says that a lot has changed for him since Tsukasa invited him to join Wonderlands x Showtime, and KAITO remarks to himself that Tsukasa has been a positive influence on him.

Revival my dream
In the second side story of Tsukasa's "An Officer's Crisis" card, Tsukasa remembers what happened during the Halloween show and starts to worry that Rui will hold back again in their current performance, as it also involves a risky stunt that had almost injured Emu earlier in the story. This leads to him staring at Rui out of concern as the group take a break from their rehearsal until Rui notices and asks him if there's something wrong. Nene eventually points out why he's worried, and Rui reassures him that he's okay this time, saying it's all thanks to Tsukasa for going all out with his directions back during the initial issue.

On the Stage of Dazzling Light
During the event, Rui worries about not being a good director for Tsukasa as he feels he held him back by not giving him enough different roles in their shows, and he spends most of the event looking for ways to help Tsukasa with their upcoming performance. His 4* card story also showcases this, as much of chapter 1 is him talking about Tsukasa and asking Miku if she can help him out. The two of them also have a duet section in the event's song, "88☆彡," as well as extra illustrations in the song's 2DMV.

The Gentleman Thief's Thrilling White Day?!
During the After Event Virtual Live, Rui mentions wanting "to make a chocolate statue of Tsukasa-kun and then having the real Tsukasa appear from inside of it". When Tsukasa asks how he'd do this, Rui whispers something to him, and Tsukasa then reacts humorously asking how that'd even be possible. The two are so busy whispering to each other that Len has to close the live on their behalf.

A Sorrowful Farewell at the Curtain Call
At one point in the event, there is a train scene where Rui and Tsukasa are having a conversation about their futures while Nene and Emu are sleeping. Later, Tsukasa falls asleep, and Rui laughs at his snoring.

A Once-In-A-Lifetime Pandemonium?!
Tsukasa asks to go out with Rui to a stage and the parade for the second day of their school trip, and Rui accepts. At the end of the first day of the event, Tsukasa goes to see how Rui's doing as a teacher begins to suspect that Rui is doing something shady and then is invited to play a game called 'President' with Rui and his other group members, Taniyama, Miyake and Hayashi. As Tsukasa loses the game 5 times, he then leaves and Rui starts to chase him. They both get caught later. After the second day, after they both have to write an apology letter for their pillow fight, Rui thanks Tsukasa for giving him the chance to change, and Tsukasa tells Rui that he chose to change with the choices that he made while being with the troupe. After that, Rui invites Tsukasa to walk along Kamo River early in the morning with him and watching the sunrise with him. Afterwards, when Tsukasa gets caught not writing in the aforementioned letter, Rui thinks about how Tsukasa brings endless smiles to his face.

Other Content
In Tsukasa's 2021 birthday lines, it is stated that Rui made him a celebratory cannon filled with confetti, the dialogue being: "Tsukasa-kun, look! All of the confetti flew up so high. Now, if they manage to spread out beautifully, this will be a huge success!" To which, Tsukasa's response was "Ooh! The celebratory cannon made by Rui is amazing! It looks like as the whole school is covered in a flurry of confetti!" This is also confirmed by Nene and Emu, both mentioning the huge cannon.

In Rui's 2022 birthday card lines, Mizuki remarks that they've noticed Rui's changed a lot for the better since they knew him, and wonders if it's because of Tsukasa's influence. Tsukasa also tells Rui not to hold back with shows or even in private, and to tell everyone if there's anything he wants to do with them.

In the Wonderlands x Showtime 1st Connect Live "Stories", both Rui and Tsukasa dance together in their KING choreography, Rui imitates Tsukasa, and during the 88☆彡 performance, Rui is looking at Tsukasa as everyone else on stage has their eyes closed. Tsukasa also thanks Rui for giving everyone the chance to stand on the stage.

Fanon
RuiKasa is widely considered to be the most well-known and most shipped slash ship in the fandom. The ship is supported mainly due to the pair's natural chemistry, and also the fact that they're both very popular characters. It is the most written ship on AO3 with over 2000 works; even managing to get into the Top 100 ships in AO3 of 2022. They are also the ship with most works on Pixiv as well. It's mainly rivalled by Ruinene and Emukasa, as well as Ruiemu and Nenekasa, but it's also common for all five ships to be shipped within Polyshow. RuiKasa also has slash ship rivals as well, with some also shipping all four of the game's male characters together as the poly ship Fantasista Squad. RuiKasa is often shipped alongside Emunene.

Tsukasa and Rui are often perceived as a sun and moon duo, with Tsukasa being the sun and Rui being the moon. This is due to Tsukasa and his cards being lighter and brighter in color scheme while Rui and his cards are darker in color scheme. People have also pointed out that the moon appears in Rui's fragment SEKAI while Tsukasa strives to be a star, which is what the sun is. Nene also walks away from Rui and Tsukasa in the Kami no Manimani 3DMV while she sings the line "And sleep without regard for the sun or moon." After the "Towards the Phoenix at the Sky's Edge" event, fans have said that Rui and Tsukasa are swapping places, with Rui becoming the sun and Tsukasa becoming the moon, but the majority of people still view Tsukasa as the sun and Rui as the moon.

A RuiKasa Ship Week was held from December 25-31, 2022. Prompts for the first day were "holiday, confession or hanahaki", "angst, dressing up or unit swap" for the second day, "future, AU or piano" for the third day, "first meetings, sleepover, cooking or baking" for the fourth day, "sick day, magic or personality swap" for the fifth day, "practice kiss, first date or classic plays" for the sixth day, and seventh and final day was free choice.

The second RuiKasa Ship Week was held from July 12-18, 2023 under the. The prompts were "summer festival, mythology or soulmates" for the first day, "beach, stargazing or AU" for the second day, "amusement parks, song or horror" for the third day, "bad weather, ocean or music" for the fourth day, "vacation, hospital or detective" for the fifth day, "flowers, angst or cats" for the sixth day, and seventh and final day was free choice.

Fandom

 * FAN FICTION


 * FAN ART


 * TUMBLR


 * TWITTER
 * @ruikasaweek on Twitter
 * @daily_ruikasa on Twitter
 * @ruikasaweek on Twitter
 * @daily_ruikasa on Twitter
 * @ruikasaweek on Twitter
 * @daily_ruikasa on Twitter
 * @ruikasaweek on Twitter
 * @daily_ruikasa on Twitter

Trivia

 * Their ship is referred to with the "🎈🌟" and "💜💛" emojis.
 * Their Kizuna Rank titles include: "Weirdo Combo", "Top☆Star?!", and "The Best Show".
 * They have a height difference of 9 cm, Tsukasa being 173 cm and Rui being 182 cm tall.
 * Some of their Cheerful Carnival Team names are "Drone Chasing" and "That's a NO For Me".
 * They currently have covered 5 songs together (,, , and ), two of which being without an accompanying VIRTUAL SINGER. They also both have solo versions of Rui's second commissioned song,.
 * Nonsense Bungaku was given to them as a duet (feat. Len) during the Eve tie-in. It is about someone who was lonely but starts trusting again after they meet a certain person, which is reflective of Rui's development with regards to Tsukasa throughout the game's story.
 * In the KING 2DMV on Project SEKAI's official YouTube channel, they are shown as playing cards with Tsukasa as the king and Rui as the joker.
 * In the 3D performance of the same song during Wonderlands x Showtime 1st Connect Live STORIES, their choreography during the pre-chorus featured both of them reaching out to each other and Rui tilting his head backwards when Tsukasa's hand was below his jaw.
 * On September 21st, the Fixer 2DMV premiered. September is the 9th month, and 21-9 = 12. Within the MV there are secret codes. These codes can roughly be translated to "Every human walks around with a different kind of suffering" and "A drowning man will clutch at a straw."
 * At the end of the music video, their bodies turn each other's respective colors, with Tsukasa's body turning purple and Rui's turning yellow.
 * In the Sweet Magic 3DMV, Tsukasa runs over to Rui and gives him a fistbump with a wink and smile.
 * The song commissioned for Wonderlands x Showtime's Main Story,, mentions a "thick-skinned king" and an "alchemist full of desires", referring to Tsukasa and Rui respectively.
 * In Nene's initial 3* second card episode, she tells Emu that Rui and Tsukasa had to stay back at school for detention because Tsukasa almost got blown up in the school's swimming pool.
 * Their image and hair colors, yellow and purple, are complementary colors. Their secondary hair colors, orange and blue, are also complementary.
 * As of the "Connecting Painful Hope" event, Tsukasa is the character Rui has mentioned the most in his stories, at a total of 329 times. This is over 100 times more than Nene, who is second at 197.
 * In their 2022 birthday card art, Rui wears a white cravat while Tsukasa wears a yellow necktie. In their unit outfits, Tsukasa wears a white cravat while Rui wears a yellow necktie.
 * Additionally, the flower Rui is holding in his card is an aster, which means "star," and Tsukasa is associated with the stars.
 * Tsukasa and Rui are often respectively associated with the numbers 1 and 2 both in the game and in promotional material.
 * Their first Kizuna title is "Henjin 1 2" in Japanese.
 * Tsukasa was one of the limited cards for the game's first anniversary event, and Rui was in the second.
 * Rui's 3rd Anniversary artwork from A Once-In-A-Lifetime Pandemonium!? Chapter 8, is the scene where he has a pillow fight with Tsukasa, Taniyama, Miyake and Hayashi. Additionally, the artwork was posted on the 18th, 12 days before the 3rd Anniversary.
 * During their Romeo and Juliet rehearsal in the "Kamiyama High Festival!" event, the ost, which was played, is called "A True love song" and it's track number "12".
 * Their art for the summer memory photos was posted for day 12 on the 21st.
 * Additionally, Tsukasa's promotional art for the game's second anniversary was posted on day 21, however Rui's was posted on day 13 rather than 12.
 * In their unit's cover of, they are the ones to say the "one, two" lines at the beginning of the song.
 * Some fans like to believe that there is a correlation between certain lyrics in and, Tsukasa's second focus song and Rui's third focus song respectively. During the bridge of 88☆彡, the part only sung by Rui and Tsukasa, Tsukasa's line is "I wish happiness will come to that kind of you," meanwhile Rui's final solo line in DonKetsu is "I know the ending will be a happy one."
 * In 's 3DMV, Rui sings the line "Loneliness melts away with the touch of passion" while he waves to Tsukasa.
 * In Rui's 4 star card, "Appreciate That Spirit of Yours" from the On the Stage of Dazzling Light event (Tsukasa's second focus event), the book he holds has stars on it that very closely resemble those in the Nonsense Bungaku 2DMV.
 * Rui and Tsukasa's Mastery Rank 5 outfit variants from the On the Stage of Dazzling Light event share the same/similar colours.
 * Additionally, their "Sorrow Farewell At the Curtain Call" (Rui's third focus event) outfit variants from Mastery Rank 1 reflect each others default outfits from that event; Tsukasa's MR1 variant shares the same colours as Rui's normal "Hourglass Tuxedo" outfit, and vice versa for Tsukasa's "Advanced Tuxedo" outfit.
 * On September 4, 2023, the official Opera GX account on Twitter replied to a Twitter post about RuiKasa's "moonphases" with the caption "OPERA????", before making a reply to their first tweet saying "I will not make a definitive statement whether or not I ship Ruikasa. I shall remain ambivalent."
 * In the "Revival my dream" event, Rui's second focus, it was revealed that Rui's parents were "Two Weirdos". Like his mom, Rui met another weirdo, Tsukasa, who are "Oddball 1-2" together at school. Tsukasa and Rui can be said to be made as a parallel to Rui's parents (Two Weirdos at school).