Emma is a character in Pokémon X and Y who appears in the post-game Looker storyline in Lumiose City. She is an orphaned 16 year old who was originally the boss of the Lumiose Gang, but later comes to live with Looker at the Looker Bureau and work as his assistant. She owns an Espurr named Mimi.
Emma is a brown-skinned 16-year-old girl with black hair and dark blue eyes. She wears her hair in large twintails that end in two spikes on either end, and two large bangs in front. She wears a light blue shirt with orange pleats and a white collar that has a yellow patch on the right side of her stomach.
The player first meets Emma during their first case with Looker, which involves children hanging out in the alleyways of Lumiose City. It turns out that the children were only playing with and protecting Emma and Mimi. Emma is then invited by Looker to come live at the Looker Bureau and work as his assistant. Emma is interested in the offer, but doesn't want to leave Mimi behind. Looker says that Mimi can come too, but she runs off due to being scared of adults. After the player finds Mimi and befriends her, Emma is much friendlier with Looker and accepts his invitation, going back to the Looker Bureau with him, Mimi and the player.
During the next case, Emma returns to the Bureau to find a Japanese tourist shouting insults at Looker, who had left moments ago because he thought the tourist wanted tea. Emma tries to defend Looker, while Mimi translates the ensuing conversation telepathically for the benefit of the player and, who finds out that the tourist's Pokémon were stolen at the Lumiose Station. When Looker returns and learns of the woman's trouble, Emma tries to discourage him from helping her, but he insist's that anyone who's in trouble deserves their help, and heads for the station. Emma then begs the player to go help Looker, because his only Pokémon died during one of his previous cases and he is thus defenseless.
The culprits behind the theft turn out to be a trio of gangsters called the Lumiose Gang, who had stolen the tourist's Pokémon in order to lure Looker to their turf for a challenge. Emma had unintentionally become their leader by beating them in a fight, but she stopped hanging around with them when she come to live at Looker's agency. She demands the gangsters give back the Pokémon they stole, to which they agree.
Emma later stars to worry that she and Mimi are a financial burden on Looker, and although he assures her that they have enough to get by, she still feels guilty and goes to apply for part-time work at a café she saw was hiring earlier, which happens to be the Lysandre Café. There, she ends up becoming the test subject for Xerosic's latest invention, the Expansion Suit, which gives her superhuman physical abilities, and the abilities to override a Poké Ball's programming and change her physical appearance, but also removes her free will and puts her under Xerosic's control.
For her first test, Xerosic orders her to break into the Lumiose Museum and vandalize one of the paintings there. Afterwards, she starts lurking in dark alleyways and challenging people to Pokémon battles, taking the Trainers's Pokémon afterwards. This catches the attention of Looker, and he works with the player to catch the culprit. When she is cornered, Mimi runs up to her, making Looker realize her true identity. Essentia tries to attack Mimi, but Xerosic's control over the Suit begins to malfunction, forcing her and Xerosic to flee the scene and temporarily suspend the tests.
The next day, Looker sends the player to apprehend Xerosic at Lysandre Labs. After the player defeats Essentia in a series of four battles, Looker arrives and demands Xerosic to release Emma. Xerosic's control over the Suit starts to malfunction again, and Xerosic agrees to Looker's demand, allowing himself to be arrested.
After Xerosic is brought to justice, Looker reveals to Emma that he is a member of the International Police, and that he must leave to continue his civic duties. However, to ensure that Emma has a bright future, he buys the entire building that the Looker Bureau was located in, and tells Emma it is hers to use however she sees fit. Emma becomes the new head detective and promises to keep Lumiose City safe with her identity as Essentia, using Xerosic's Pokémon and the Expansion Suit that he gave to her.