If you've been playing Project Sekai: Colorful Stage! feat. Hatsune Miku, you know the thrill of seeing your favorite characters crossover with other beloved franchises. The game has built an impressive track record of collaboration events throughout 2025 and 2026, bringing together everything from rhythm game classics to anime hits and even unlikely commercial partnerships. We're laying out the complete timeline of what these collaborations offered, when they ran, and what players actually got to experience.
The most recent major collaboration, "The Music Style," wrapped up on September 13, 2026, leaving players wondering what might come next. Here's everything we know about Project Sekai's collaboration history and what each event brought to the table.
The Quick Version
- The Music Style Vocaloid collaboration ran September 3–13, 2026, featuring original songs by Amala and Satsuki with special character content
- 2026 saw rhythm game crossovers with DEEMO and Cytus in June, plus a reported collaboration with Ensemble Stars!! in April
- Major 2025 events included Persona 5 Royal, Touhou Project, and Tamagotchi collaborations, each bringing limited gacha and exclusive content
- The Sanrio Characters collaboration was popular enough to receive a revival event in February 2026
- No new collaboration has been officially announced beyond October 12, 2026
The Most Recent Collaboration: The Music Style
The Music Style collaboration represented something different from Project Sekai's typical crossover formula. Rather than partnering with another franchise, this September 3–13, 2026 event centered on the Vocaloid music ecosystem itself—the very foundation of Hatsune Miku's existence. The collaboration commissioned new songs specifically for the event from producers Amala and Satsuki, both known within the Vocaloid community.
What made this event stand out was its focus on visual storytelling through music. Players received limited ★4 character cards featuring special hairstyles that connected to the themed song worlds. The event blended Project Sekai's virtual singers with scenarios inspired by specific Vocaloid compositions, creating what the developers described as a fusion of character narrative and musical universe.
Since The Music Style ended in mid-September, there hasn't been an officially confirmed collaboration running in October 2026, leaving players in a quieter period between major crossover events.
Summer 2026: Rhythm Game Crossovers
June 2026 brought Project Sekai into conversation with two other major names in the rhythm game world: DEEMO and Cytus. The collaboration ran from June 21 through July 3, 2026, and focused on the addition of "SAIRAI" to Project Sekai's playable song library. This track bridged the atmospheric storytelling that DEEMO and Cytus are known for with Project Sekai's colorful character-driven style.
The DEEMO × Cytus collaboration included several player-friendly features beyond just the new song. A login campaign rewarded players simply for showing up during the event period, while premium present gacha offered collaboration-themed items. Stamp missions gave players specific goals to complete for rewards, creating multiple paths to engage with the crossover content.
This wasn't just a song drop—it represented a rare moment of crossover between three titans of the mobile rhythm game space, each with its own devoted community and distinct musical identity.
Spring 2026: Unexpected Pairings
The spring months of 2026 reportedly brought some of Project Sekai's more unexpected collaboration choices. According to available event listings, an Ensemble Stars!! crossover ran from April 13–27, 2026, bringing together the idol-focused rhythm game with Project Sekai's virtual singer universe. While specific details about what this collaboration included haven't been widely documented, it marked an interesting meeting point between two different approaches to music-game storytelling.
Earlier in the spring, a collaboration with the battle game Compass reportedly took place from March 14–24, 2026. This partnership was noted for specifically not including certain gacha elements that some players find frustrating, suggesting the developers were listening to community feedback about collaboration structure.
The Taiko no Tatsujin collaboration, listed as running from February 21 through April 21, 2026, had an unusually long duration that may have encompassed multiple related activities or phases. The pairing made natural sense—both games celebrate rhythm and music, though Taiko brings the traditional festival drumming aesthetic that contrasts sharply with Project Sekai's contemporary virtual idol world.
Early 2026: The Return of Sanrio
Sometimes a collaboration is successful enough that it deserves a second life. That's exactly what happened with the Sanrio Characters crossover, which returned for a revival event from February 5–19, 2026. The original Sanrio collaboration had been popular enough with players that the developers brought it back, complete with a revived login campaign that let newer players—or those who missed it the first time—experience the kawaii fusion of Hello Kitty's world with Hatsune Miku's.
The Sanrio partnership represented one of Project Sekai's more commercial collaborations, bringing together two massive Japanese cultural exports. The revival also signaled that the game's developers were willing to bring back fan-favorite events rather than treating every collaboration as a one-time-only opportunity.
2025's Standout Collaborations
Looking back at 2025, Project Sekai assembled an eclectic mix of collaboration partners that showed the game's willingness to cross genre boundaries. The Persona 5 Royal collaboration from August 4–13, 2025 brought the stylish Phantom Thieves aesthetic into the rhythm game space, letting players experience a meeting of two very different musical worlds—jazz-fusion RPG soundtracks meeting Vocaloid pop.
The Touhou Project collaboration from May 3–13, 2025 connected Project Sekai with one of Japan's most enduring fan-created game franchises, known for its bullet-hell gameplay and extensive music library. Given that both Touhou and Vocaloid have massive fan music communities, this crossover felt like a natural cultural fit.
Perhaps more surprisingly, the Tamagotchi collaboration from September 19 through October 5, 2025 brought virtual pet nostalgia into the mix. The partnership showed that Project Sekai wasn't limiting itself to obvious musical or gaming crossovers—it was willing to reach across to other corners of Japanese pop culture.
One of 2025's more unusual entries was "The Seven Deadly Sins" (Aku no Taizai) collaboration from November 21 through December 5, 2025. This event, which also received a revival treatment, likely referenced the Vocaloid song series of the same name rather than the anime of a similar title, staying within the music-focused universe that Project Sekai inhabits.
Beyond Gaming: The Sushiro Partnership
Not every collaboration lives inside the game client. Project Sekai's partnership with Sushiro, the conveyor-belt sushi restaurant chain, launched on December 10, 2025 and brought the game into physical retail space. While the exact end date for this campaign hasn't been widely documented, it represented the kind of real-world brand partnership that successful mobile games increasingly pursue in Japan.
These restaurant collaborations typically include themed menu items, collectible merchandise, or special promotional materials featuring game characters. They serve a dual purpose: giving existing players something tangible to collect while introducing the game to potential new players who might not otherwise encounter it.
What Makes a Project Sekai Collaboration Work
The term "collaboration" covers a lot of ground in Project Sekai's world. Some events are full crossovers with other game franchises, complete with character appearances and themed gacha. Others are music-focused partnerships that add new songs to the playable library. Still others are commercial tie-ups that exist primarily outside the game itself.
What we've seen across 2025 and 2026 is that the most memorable collaborations tend to share certain elements: limited-time ★4 character cards with special designs, login bonuses that reward participation without demanding extensive grinding, and thematic coherence that makes sense for both properties involved. The rhythm game crossovers (DEEMO, Cytus, Taiko no Tatsujin) feel natural because they share musical DNA. The Persona 5 Royal collaboration worked because both games have strong visual identities and music at their core.
The collaborations that seem to generate less discussion are those that feel more transactional—basic promotional tie-ups without much creative integration. Players respond when they can tell that thought went into how two different universes might authentically intersect.
Looking Ahead: What's Next?
As of October 12, 2026, no new collaboration has been officially announced for Project Sekai. The game recently celebrated its sixth anniversary with the Thanksgiving Festival at Tokyo Gymnasium on October 3–4, 2026, suggesting the development team has been focused on milestone events rather than external crossovers.
The pattern we've observed suggests collaborations tend to run for roughly two weeks, with the longest stretching to about a month. They often arrive during specific seasons or to mark game anniversaries. Given that we're in a quiet period, many players are watching the official Project Sekai news channels for hints about what might be coming before the year ends.
The game has also been running creator-focused initiatives, like the Project Sekai Creators Festa held on May 30–31, 2026, which celebrated the community of artists, musicians, and content creators who have built up around the game. These events signal that collaborations aren't just about bringing in external franchises—they're also about recognizing the creative ecosystem that players themselves have built.
What People Are Saying
"The Music Style collab felt like it went back to what makes Project Sekai special in the first place—the Vocaloid music and letting those songs tell stories. Sometimes the best crossover is just celebrating your own roots."
— Player discussion on social media, September 2026
"I'm still sad I missed the original Sanrio event, so when they brought it back in February I made sure to grab everything. The revival campaigns are actually a really player-friendly move because not everyone was around for the first run."
— Reddit rhythm game community member
"The DEEMO and Cytus crossover was such a good choice because we're all rhythm game nerds anyway. Getting to play SAIRAI in Project Sekai's engine felt like worlds colliding in the best way."
— Rhythm game enthusiast on fan forums
"Honestly the Persona 5 collab was what got me to actually download Project Sekai. I came for the Phantom Thieves aesthetic and stayed because the core gameplay is actually really solid."
— New player testimonial, late 2025
Frequently Asked Questions
Is there a Project Sekai collaboration running right now in October 2026?
No officially confirmed collaboration is running as of October 12, 2026. The most recent major collaboration, The Music Style, ended on September 13, 2026. Players are currently waiting for announcements about upcoming events.
Do Project Sekai collaborations come back, or are they one-time events?
Some collaborations do receive revival runs. The Sanrio Characters collaboration returned in February 2026, and The Seven Deadly Sins collaboration also had a revival in late 2025. However, not all collaborations are brought back, so there's no guarantee that any specific event will return.
Where can I find out about new collaborations when they're announced?
The official Project Sekai news page (accessible through the game's website and in-game news section) is the most reliable source for collaboration announcements. The game's official social media channels also share news about upcoming events, typically giving players several days' notice before a collaboration begins.
Do I need to spend money to participate in collaboration events?
No. While collaborations typically include limited gacha that uses the game's premium currency, they also usually feature login campaigns, stamp missions, and other free participation opportunities. You can experience collaboration content without spending money, though obtaining specific limited character cards may require gacha pulls.
What was the longest-running Project Sekai collaboration?
Based on available information, the Taiko no Tatsujin collaboration reportedly ran from February 21 through April 21, 2026, making it approximately two months long—significantly longer than the typical two-week collaboration window. However, this extended period may have included multiple phases or related campaigns rather than a single continuous event.
The Collaboration Philosophy
What Project Sekai's collaboration history through 2026 shows us is a game that's genuinely curious about where its music-driven world can intersect with other creative universes. The mix ranges from obvious rhythm-game partnerships to unexpected brand crossovers, from deep fan-culture connections like Touhou Project to mainstream commercial tie-ups like Sushiro. Each collaboration tests a different hypothesis about what players want from these crossover events.
The rhythm game collaborations celebrate shared musical passion. The franchise crossovers bring fresh aesthetics and introduce new audiences. The music-focused events like The Music Style remind players why they fell in love with Vocaloid culture in the first place. Even the commercial partnerships create tangible touchpoints beyond the screen.
As we wait for the next collaboration announcement, the history laid out here shows that Project Sekai's developers have been willing to experiment broadly while maintaining respect for both their own game's identity and the properties they partner with. That balance is what keeps these events feeling special rather than formulaic, and it's what keeps players checking the news feed hoping to see what unexpected crossover might arrive next.
