"Soreike! Anpanman Omocha no Hoshi no Nanda to Runda" is a feature-length anime film based on the popular "Anpanman" franchise, which centers on the adventures of Anpanman, a superhero made of anpan (a sweet bread filled with red bean paste). The story unfolds in a whimsical world inhabited by anthropomorphic food characters and other fantastical beings.

The narrative begins with Anpanman and his friends living peacefully in their world. However, their tranquility is disrupted when a mysterious spaceship crashes nearby. The ship carries Nanda and Runda, two toy-like aliens from the distant Planet Omocha. Nanda is a cheerful and curious character, while Runda is more reserved and cautious. The duo explains that their planet is in peril due to the malevolent King Holstein, who has enslaved its inhabitants and seeks to conquer other worlds.

Anpanman, driven by his unwavering sense of justice, decides to help Nanda and Runda. Alongside his friends, including Baikinman (a mischievous antagonist turned occasional ally), Shokupanman (a bread superhero), and others, Anpanman embarks on a journey to Planet Omocha. Their mission is to free the planet from King Holstein's tyranny and restore peace.

The group faces numerous challenges as they navigate the alien world, encountering strange creatures and overcoming obstacles. King Holstein, a formidable foe with a mechanical army, poses a significant threat. The story emphasizes themes of bravery, friendship, and teamwork as Anpanman and his companions work together to outwit the villain and liberate the oppressed inhabitants of Planet Omocha.

Throughout the film, the characters' unique abilities and personalities play crucial roles in their success. Anpanman's selfless nature and willingness to share pieces of his head (which regenerate) to help others symbolize his role as a beacon of hope. The dynamic between Nanda and Runda adds emotional depth, as their bond strengthens through shared adversity.

The climax involves a dramatic confrontation with King Holstein, where Anpanman and his friends must use their combined strengths to defeat him. The resolution highlights the triumph of good over evil and the importance of compassion and unity. The film concludes with Nanda and Runda returning to their revitalized planet, expressing gratitude to Anpanman and his friends for their heroic efforts.