Sorellona serves as an assistant at a dental clinic in a small Japanese town. She wields the supernatural ability to transform ordinary objects into living creatures; discarded soda cans become penguins under sunlight, and chess pieces turn into bats in darkness. This power correlates with weather conditions and appears intrinsically linked to a mysterious floating sphere of water, known as "the Ocean," located within a nearby forest.

Her background remains largely undefined, though she recalls growing up near the coast and mentions her parents. Evidence suggests she originates from or possesses an intrinsic connection to the alternate dimension represented by the Ocean sphere. Her physical well-being diminishes when traveling far from the town, and creating multiple penguins significantly weakens her. This strain prompts the sphere to generate predatory entities called Jabberwocks that attack the penguins and accelerate the sphere's expansion.

Sorellona develops a mentorship with Aoyama, a scientifically-minded fourth grader, teaching him chess and involving him in investigating the penguin phenomenon. She acknowledges the mystery surrounding her own existence, encouraging his curiosity without providing direct explanations. Their relationship includes a one-sided romantic attraction from Aoyama, which she tolerates but does not reciprocate.

During the sphere's dangerous expansion, Sorellona collaborates with Aoyama to generate a large group of penguins. Together, they enter the sphere, traveling to a future apocalyptic version of their world to rescue researchers trapped inside. Following this mission, the penguins destroy the sphere, causing its water to flood into the real world. In the aftermath, Sorellona shares a final conversation with Aoyama at a café before embracing him and disappearing. Her departure coincides with the vanishing of the last penguin, leaving behind only the Lego probe previously absorbed by the sphere as evidence of their experience.