Bianca is a primary character in Pokémon Heroes. She is the granddaughter of Lorenzo and the best friend of Latias, who has a tendency to shapeshift into her. Bianca has a hairstyle similar to Latias's but can usually identified by the white beret she wears. It appears she wishes to be a painter or possibly a Pokémon Watcher similar to Tracey Sketchit. She is a nice girl but can be harsh and defensive at times

Bianca first appears in the museum, drawing some of the stain glass windows in the museum. Ash is distracted by her, since he previously saved Latias in the form of Bianca and believes she is the same girl he rescued. Wanting to know why she disappeared after he saved "her", Ash and Pikachu pursue her across Alto Mare, finally catching up to her on the other side of the bridge, but Bianca is confused by his questions and quickly departs. Ash loses track of Bianca but instead follows Latias to the secret garden. As Latios attacks Ash, Bianca appears and believes Ash is the one attacking. Lorenzo soon appears and stops the fighting, Bianca believing that Ash was trying to harm Latios. She soon learns the truth and apologizes for her actions, becoming friends with Ash. She is later captured along with Lorenzo in the museum and held hostage, and tells Latios to use Sight Sharing to bring Ash and Latias to the museum. Bianca and Lorenzo are freed and help save Latios from being tortured. Bianca is deeply upset by Latios's sacrificial death and receives the new Soul Dew.

The conclusion of the film briefly sees her finishing a drawing. The drawing, which is of Ash and Pikachu, is given to Ash by either Bianca, who had left her hat on her easel, or Latias in the form of Bianca: which is the case is the subject of debate. When Ash received the sketch, the girl kissed him. It is unknown if this was Bianca or Latias. Bianca is seen again in the credits drawing another sketch by the harbor.