Cosmic Princess Kaguya! 2026

Iroha Sakayori [Anna Nagase] is a high school student who lives apart from her family after her father’s death, juggling classes, tuition, and a part‑time job while spending long hours in the immersive virtual realm of Tsukuyomi. One late night, a glowing pole seems to hum with energy, and inside it she finds a baby. She brings the infant home, and over the course of just a few days the child rapidly grows into a teenage girl who proclaims she’s from the Moon. She names herself Kaguya, a nod to the ancient folktale, and she is determined to craft a happier ending than the melancholy story.

Kaguya’s sudden, restless presence starts to unsettle Iroha’s carefully measured routine. To help navigate this new dynamic, Kaguya introduces Iroha to Tsukuyomi’s virtual administrator Yachiyo Runami [Saori Hayami], and together with Kaguya’s quirky virtual pet InuDOGE, they sign up for the Yachiyo Cup—a streamer competition whose winners earn a live show with Yachiyo herself. The prospect of fame, music, and a larger stage pulls them deeper into the world they inhabit, and Kaguya’s charm quickly makes her a popular figure online with Iroha’s support.

But success on screen invites real-world tension. Black OnyX, the top streamer collective led by Akira Mikado [Max Mittelman], takes an intense interest in their rise. The two teams are drawn into a high‑stakes challenge in KASSEN, a territorial battle game within Tsukuyomi, where loyalties are tested and strategy clashes sharpen the rivalry. A startling twist arrives when the truth about Akira surfaces: he is Iroha’s estranged brother, — a revelation that complicates loyalties and motivations on and off the digital stage.

Despite Black OnyX’s win in KASSEN, the fans rally behind Kaguya and Iroha, helping them seize victory in the Yachiyo Cup. The win secures a live show and forges a partial reconciliation with Akira, who agrees to co-sign a new apartment for the two young women. Yet triumph is tempered by a looming cosmic threat: lunar beings from the Moon invade Tsukuyomi to extract Kaguya home. They are repelled by Yachiyo, but their retreat is temporary, promising a return at the next full moon. The possibility of losing Kaguya again makes Iroha wary, and the sense that their time together may be finite weighs heavily on her.

As the day of Kaguya’s supposed departure approaches, she hosts a graduation concert within Tsukuyomi. Iroha, flanked by friends, fights to defend her, but the lunar forces ultimately abduct Kaguya. Back in the normal world, Iroha continues with life, though she cannot shake the ache of separation. She pours her longing into a song she and her father had never finished, a moment that becomes a turning point. After performing it, Iroha experiences a startling revelation and returns to Tsukuyomi, where Yachiyo reveals a shocking truth: Iroha is a future version of Kaguya herself.

The story’s layered history unfolds further: Kaguya had once attempted to travel back in time to reunite with Iroha, but her ship struck an asteroid and was cast eight millennia into the past. InuDOGE—the loyal companion who later becomes Yachiyo’s partner Fushi—served as her lifeline, communicating across the ages until Tsukuyomi was created and Kaguya was uploaded into a virtual avatar. Motivated to bring Kaguya back into the real world, Iroha rejects one path—law school—and instead works on creating an android body for Yachiyo to host Kaguya’s consciousness. The breakthrough succeeds, and the three—new Kaguya, Iroha, and Yachiyo—continue to perform, bridging both real life and Tsukuyomi as a united troupe.

The film threads themes of family, memory, and what it means to belong, set against a shimmering backdrop of digital artistry and human connection. Iroha’s steadfast care for Kaguya and her sense of responsibility toward Akira and the wider Tsukuyomi community ground an emotional arc that moves from friction and confusion to reconciliation and wonder. The Moon’s pull remains a constant, but the ending suggests that love, art, and shared dreams can bend even the most distant futures toward a brighter, more enduring harmony.

• Anna Nagase as Iroha Sakayori is introduced early as the grounded, responsible teen who becomes the anchor for the story’s emotional core.

• Jeannie Tirado as Kaguya appears as the enigmatic, otherworldly newcomer who longs for a happy ending and whose presence catalyzes most of the plot’s central decisions.

• Saori Hayami as Yachiyo Runami serves as the cool, capable virtual administrator who guides the newcomers through Tsukuyomi and anchors the live show ambitions.

• Rie Kugimiya as Fushi, the sentient companion arising from InuDOGE, links the Moon‑born quest to the evolving human world.

• Anairis Quinones as Otako the Loyal Dog contributes to the quirky, supportive network around Iroha and Kaguya in their rise to stardom.

• Max Mittelman as Akira Mikado drives the competitive energy with his formidable presence and his reluctant familial ties to Iroha.

• Cassandra Lee Morris as Roka Ayatsumugi contributes to the ensemble’s dynamics as part of the wider Tsukuyomi community.

• Casey Mongillo as Noi Komazawa adds to the colorful cast that helps ground the story’s streamer culture.

• Kieran Regan as Koto Okotteru enriches the group’s interactions and the world-building within the game’s ecosystem.