Stella is the main protagonist of Interstella 5555: The 5tory of the 5ecret 5tar 5ystem. She is the bassist of The Crescendolls, and the only female member of the band. She also has a crush Shep, the man who saved them both from Earl de Darkwood.
Stella has very long blonde hair with a full fringe, tied in a high ponytail with a silver hair clip. Her eyes are blue with yellow sclerae. She wears an outfit similar to the rest of her group, who wear orange and white uniforms. Her outfit is a white and orange high-neck sleeveless long gown with a large heart shape design that shows her cleavage. There is also another small heart shape design which is upside-down, to show her mid-bottom with a white ribbon which is hanging loose on her back. She wears white warrior flats on her feet. She also wears a white headband with a red jewel at the center and a matching wristband, like the other band members. When their clothes are destroyed by the machines when they are modified into humans by the Earl de Darkwood, she wears only a strapless white bra and a matching panties.
As a child during Daft Punk's Harder, Better, Faster, Stronger, Stella's appearance remains the same as her adult self.
After her appearance was modified to resemble a human, her skin has been painted fair, her hair becomes burnt orange instead of blonde, and her eyes become brown instead of blue. Her hair is cut to a loose shoulder length with a pink hairclip at the center. She wears a dark pink western-style collared jacket with a green tank top that shows her lower abs, a brown short skirt with a black belt with a gold heart buckle, and matching brown boots with green knee length socks. She also wears a black necklace with a dark pink pendant on her neck and several bracelets on each of her wrists. Her cat's eye sunglasses from her mind control device are transparent pink, but she was later freed by Baryl during the awards night. Her sunglasses are later discarded and replaced with a white flower daisy at the left side of her head, after Shep gives her the triangular device to show the band their true identity before he dies.
During the awards night, she wears a cyan and white long sleeve v-neck sparkling gown with baggy sleeves, which also shows her cleavage like her original outfit, and has a purple belt adorned with a purple ribbon at the back. The front skirt of her dress is short and at the back it goes down to her feet. She also wears black flats with gold anklets. She also wears a gold hairclip with matching ornaments, but maintains her black necklace with a dark pink pendant from her casual outfit.
During her dream sequence with Shep, her sparkling gown changed to white and she was seen in her original appearance instead of her human appearance.
When the Earl copies the band's childhood memories by storing them inside the disc during her modification as a human like the rest of the group, Stella's appearance remains the same as her adult self and her eyes remain brown. She wears a blue short sleeved collared dress with a yellow ribbon at the center, yellow socks, and black flats.
Unlike most anime girls in different media, Stella is shown to be a calm and serene woman when she is playing her bass guitar. During the time in which most of Daft Punk's songs are played, Stella is displayed as the damsel in distress and was the main reason why Earl decides to block her when Shep attempts to free her from his mind control. Earl had intentions of using her as a vessel to control the machine with several discs to rule the whole universe, as seen in Veridis Quo. Despite this, Stella was also happy when she was rescued by Shep in his spiritual essence. She is also very grateful towards others.
Stella is the only female band member within Octave's band called The Crescendolls and is the bassist of the group. She was seen being partnered by Arpegius while performing their guitars during the concert in One More Time. She might have a crush on Shep, who displays feelings towards her in the movie. The concert was later disrupted by Earl de Darkwood and his humanoid troops. She was gassed along with Octave and Baryl to be captured, and later Arpegius who was knocked down during his brief escape by one of the Earl's humanoid troops with an arrow shot full of gas. The group are soon kept by Earl from his spaceship and are taken to Earth to be modified as humans under his mind control.
When Arpegius, Octave and Baryl are freed by Shep who disrupts the orchestra concert lead by the Earl, Stella was the only person not to be freed due to Earl blocking Shep from hitting her. Shep is mortally wounded, meanwhile Stella wears a gown for the awards night and assists Earl, and they go to Veridis Quo manor. She was later freed by Baryl after they gained the golden disc award as she follows Baryl to find Shep in Octave's taxi. Shep in his last breaths gives a triangular device to Stella to show their real identity and to let them know he saved them. He tells Arpegius to take care of Stella before dying as the group mourns for his death. When Stella touches Shep in his wounded state, a sequence occurs where the two share a dream sequence, akin to the one in Digital Love.
The group soon enter Darkwood manor to find out Earl's motives. Stella was the only person to be caught by Earl to be made a vessel to rule the universe. However, his plans are foiled when Arpegius angrily tackles him to the ground as the last golden discs fall into the oblivion, taking Earl with them.
As the group returns to their original forms, Arpegius makes peace with their producer. As they fly through space and enter the wormhole, they are attacked by Earl's spiritual essence until Shep's essence saves them, greeting Stella with a smile. The group safely continues on their way.
Stella is last seen having a concert one final time with the group, and at the unveiling of Shep's statue in memory of him. During the ceremony, Stella looks at the bright purple star, smiling knowing that it is Shep's spirit.
She and Shep are last seen as two of the young boy's small dolls, lying beside him.