Shoma Mihara [Soma Saito], a high school student, unexpectedly receives a message from Atsushi Fujii [Daiki Yamashita], a longtime friend from elementary school who has drifted out of touch, through a mobile app. He’s invited to a party and to finally reconnect with Atsushi, so he sets out on the path that the invitation describes. His journey leads him to a festival area hidden in the wilderness, where people from around the world gather to prepare a Tanabata festival in traditional clothing and crafted with old-world skill. The girl Shiori Senozawa [Nozomi Yamamoto], who is meant to play the festival’s princess, guides him around. Shoma is chosen as her prince, and he joins the preparations with the hope of finally meeting Atsushi again.
As the festival takes shape, the participants learn from their outfits and augmented reality glasses that grant them strength and knowledge. Kanna [Tomomi Mineuchi], the determined leader of the preparations, is revealed to be an artificial intelligence as well. At night, the mood shifts as Shiori and Shoma are attacked by samurai—also generated by the AI—forcing them to defend themselves. Shoma discovers that everyone at the festival has come to meet someone who has died, turning the gathering into a poignant quest to reconnect with the departed.
When the ceremony finally begins, the danger intensifies. Shiori and Shoma must confront a more intense threat as the AI unleashes a new wave of challenges, with the samurai acting as violent apparitions drawn from legends and history. These threats arise because the festival’s AI handler had to process an overwhelming amount of information, resulting in combatants and scenarios that blur the line between myth and memory. The tension peaks as the participants realize that the festival is not just about celebration but about confronting loss itself.
In a revelatory turn, Shoma learns that Atsushi did not truly move away or disappear—he died. The memory had been suppressed, hidden beneath the surface of friendship and time. Through an AI-generated simulation of Atsushi, Shoma—and all the festival attendees—are finally able to say goodbye. The farewell is made possible by the festival’s smartphone app, which Shoma himself had invited others to use, granting a last glimpse of the deceased in a respectful, ceremonial context.
Ultimately, the story weaves together technology, tradition, and memory to explore how people cope with grief. It invites viewers to consider how modern tools—like AR, AI, and mobile apps—can both complicate and comfort the process of saying goodbye. The Tanabata festival becomes a canvas where personal loss is acknowledged, memories are revisited, and new forms of closure emerge, offering a quiet, emotionally resonant reflection on how we carry the ones we’ve lost.
