For the large portion of her life, Nathalie has been raised in her hometown of Toamasina in the country of Madagascar. As a child Nathalie has always exhibited a strong interest in two things: the ocean and reading. It was not uncommon to find little Nathalie running along the water's edge on the sandy beaches or playing happily in the waters as she collected seashells. Other nights one could most certainly find her holed away in her room with her nose deep in a book detailing alien languages as she attempted to make sense of the words.

On her fifteenth birthday, Nathalie made the decision to travel Terra before she would finally decide on where to go next in her life. Traveling the globe from country to country Nathalie met many different people and discovered many other cultures unlike her own. Upon visiting in Tokyo, Japan, Nathalie instantly fell in love with the art of Calligraphy. Spending a month there Nathalie studied and learned not only the country's language, but she also discovered the beauty and quality of meditation. Further travels Nathalie learned many things about electronic equipment used in the past by other cultures and the things that they used today. Eager for knowledge, Nathalie spent a majority of her time visiting the museums, researching or holed away in the libraries reading up. Soon Nathalie's journeys led her back home.

Five months before Nathalie's sixteenth birthday was to arrive, Nathalie met head on with death itself. A true lover of water and racing, Nathalie had a natural affinity towards racing on Wave Runners or Flight Bikes. Not one to turn down a good challenge Nathalie participated in the annual racing tournament that was to be held every year near the waters of her home. The taste of victory was near for Nathalie as she prepared to face the final lap of the race, however a horrendous riptide pulled both Nathalie and machine out far into the water. Thinking nothing of it, Nathalie hit the gas full throttle and the machine collided with a piece of coral reef, not only pulling her underwater but also tossing her straight into a nest of jagged rocks. Her ride collided into her, virtually shattering her spinal cord to pieces. The race had been cut short that day and Nathalie was immediately rushed to Starfleet Medical.

It was soon discovered that Nathalie's spine had been fractured, and her diagnosis was not good. Though her spine was replaced and restored through surgery, she would always carry its injury. During her recuperation period Nathalie was able to regain movement as well as the ability to walk again. Humiliated by her foolishness, Nathalie made the decision to change her life and put her skills to good usage. That thought in mind, Nathalie told her mother and father she wished to attend Starfleet Academy. Nathalie, determined to find her place in life, enrolled into the Academy as planned. During her time in the Academy Nathalie extensively studied four major languages being Andorian, Bajoran, Betazoid, and Vulcan.

During her Senior Cadet Cruise, Nathalie continued her studies in the areas of Risan and Trill. This approach, whilst rigorous and demanding mentally, she worked hard to learn each language and upon graduation she had graduated amongst the top 5% of her class in the area of Communications. Shortly after graduating, Nathalie spent a year at the place she was enrolled her Senior Cadet year: the USS Phoenix. A few years later, Nathalie was assigned to San Drego Colony.

Her skills were noticed and four years later, Nathalie moved on to join the crew of Deep Space Nine. During her time aboard the station Nathalie met many different kinds of people and cultures. Working primarily as a Communications Specialist, Nathalie also took up a side job aboard the station and she had resorted to teaching languages to the training cadets and crewman who were to be serving onboard starships or to continue later working onboard the station itself.

Thinking she had finally found her place amongst the station's crew, Nathalie began to wonder if she would be of any greater use elsewhere, such as back aboard a starship. Nathalie was more than surprised when she received a message from SFC requesting that she consider transferring to the USS Hikaru Sulu.

Nathalie Gui is best known as coming across as brash and strong willed. She possesses a feisty attitude and she has been known to be temperamental; one minute she could go from being angry and the next to being in tears. One would probably naturally think given this personality disposition she's a Counselor's nightmare. However Gui more than makes up for it in her duties. Nathalie also has been known to have a peculiar outlook on things from time to time; in the end, however, she is more or less being down to earth and truthful.

On duty Gui keeps a cool head under pressure, and she handles things calmly. Analytical, her mind is always working, trying to find the positive aspect out of a dead-end situation so that she may work around it; in fact she always tries to better understand a problem so that if she comes face to face with a similar problem or situation again, she knows how to better tackle it head on. A very diligent worker she is always striving to do better.

One of the many things Nathalie values most above anything else is friendship; once someone has earned her trust and friendship she will be a true friend to the very end.

On her lower right ankle Nathalie has the tattoo of a shooting star done in black ink. Running down the length of Nathalie's back, starting just below her shoulder blades, left of her spine, is a tattoo of a hammerhead shark done in blue ink, swimming upwards, a wave trail beneath it. The shark's body has the designs of ocean waves on it. Down Nathalie's spine runs a long yet noticeable scar from her accident. Her back, while it is in better condition, still needs to be examined from time to time as it sometimes causes her pain.

Nathalie's eyes are a light gray color.