"Soreike! Anpanman: Rubie no Negai" is a film adaptation within the long-running "Anpanman" franchise, which centers on the adventures of Anpanman, a superhero made of anpan (a sweet bread filled with red bean paste). The story revolves around a precious gem called the Star Ruby, which holds the power to grant wishes. When the gem is stolen by the mischievous Baikinman, Anpanman and his friends embark on a mission to recover it and protect the wishes it safeguards.

The narrative begins with Rubie, a young girl from the Star Ruby Planet, arriving on Earth to seek Anpanman's help. She explains that the Star Ruby is vital to her world's happiness and that its theft has caused widespread despair. Anpanman, alongside his loyal companions such as Shokupanman and Currypanman, sets out to confront Baikinman and his cohorts, who plan to misuse the gem's power for their own selfish desires.

As the story progresses, the heroes face various challenges, including navigating treacherous environments and overcoming Baikinman's cunning traps. The film emphasizes themes of friendship, courage, and selflessness, as Anpanman and his friends work together to restore hope and fulfill Rubie's wish. The climax features a dramatic confrontation where Anpanman must use his strength and ingenuity to reclaim the Star Ruby and ensure its safe return to Rubie's planet.

The main characters include Anpanman, the altruistic hero who sacrifices pieces of his own head to feed the hungry; Baikinman, the primary antagonist who thrives on causing chaos; and Rubie, the earnest and determined visitor from another world. Supporting characters like Shokupanman and Currypanman provide additional depth to the story, showcasing their unique abilities and unwavering loyalty to Anpanman.

The film maintains the franchise's signature blend of lighthearted humor, action, and moral lessons, appealing to its target audience of young children while delivering a straightforward yet engaging narrative. The focus on teamwork and the triumph of good over evil aligns with the core values of the "Anpanman" series, making "Rubie no Negai" a fitting addition to the franchise.