Grandis Granva is the head of the Grandis Gang, a trio of jewel thieves. Once a wealthy Italian noblewoman, she lost her fortune to a deceitful womanizer. She met Nadia while in pursuit of her jeweled necklace, the Blue Water. Later, they became friends.
There is very little info about Grandis before she appears in the show. She grew up in a royal family in Italy. Her family made their fortune from diamonds. After the mother passed away while she was a child, she inherited her mother’s jewelry box and became her father’s only woman in life. Grandis then grew up to be an elegant, spoiled and powerful young woman. At her first social party, she met and fell in loved with a man named Gonzalez and got married. Unfortunately, Gonzalez wanted to marry Grandis for her family’s fortune to payoff his debts after lying about his noble heritage. This Grandis broke and alone. It was assumed that Gonzalez divorced after stripping away her family fortune.
After her frail mistake she was exiled by her friends and family, and the only people who remained faithful and loyal to her were Hanson (the mechanic) and Sanson (the chauffeur). The two men have strong feelings for her, but Grandis does not have romantic feelings for them in return. The trio sustained themselves from Grandis’ jewels until they were all gone. When Grandis became obsessed with jewels, the trio then began their lives as jewel thieves and called themselves The Grandis Gang. The trio travel the world in their multi-purpose getaway vehicle – The Gratan (or the “Catherine” as Grandis and Sanson refer to it).
By 1889, Grandis is twenty-eight years old at the very start of the series, where she the Grandis Gang arrive in Paris, France to steal a famous, and yet mysterious, jewel called the Blue Water from a colored circus performer named Nadia. Once they tracked her down at the Eiffel Tower, Nadia easily manages to escape from them. The Grandis Gang then locates the young acrobat at a circus, where they bought her from her master to try to steal her jewel necklace. Their efforts were soon foiled by an ingenious boy named Jean, who fell in love with Nadia and rescues her. The Grandis Gang began to chase Jean and Nadia with the Grantan by land, air, and sea, on a never-ending pursuit as they become hell-bent for the Blue Water.
After a failed effort to snatch the kids from a US Navel warship, the Grandis Gang found themselves adrift until they came across an island. They island they settled on is where they located Jean and Nadia (who were sent there by a submarine called The Nautilus via aircraft) and soon were encountered masked soldiers called the Neo Atlanteans. After being captured and put to work in a slave camp, the Grandis Gang were unsuccessful to escape and were locked away in prison. They tried to escape again, they team-up with Jean as they worked together to rescue Nadia, her pet lion cub King and a little girl named Marie from a villain named Gargoyle. Although their rescue attempt was almost successful, they were outmatched by the technological science of the Neo Atlanteans. They were all eventually saved by Captain Nemo and the Nautilus crew.
Soon after the defeat of the Neo Atlanteans, Jean, Nadia, King, Marie, Grandis, Sanson, and Hanson then found themselves as guests (and later honorary crew members) of the Nautilus. While on board the submarine, Grandis falls in love with Captain Nemo. She also develops a competing and having strict rivalry with Electra, First Officer of the Nautilus. Grandis tries to seduce Nemo with any power she has until the every end, but her love for him was never returned. Grandis also befriends the children and becomes a mother-figure to Nadia.
When the Neo Atlanteans finally tracked down the Nautilus with their own aircraft, the Grandis Gang used the Gratan to defend the ship when it was pulled to the surface by a magnetic field. After a crude effort, with the Grandis Gang was caught adrift when the enemy aircraft shot a hole in the balloon. They eventually landed on a mysterious deserted island (later revealed to be Red Noah), where it exhibits strange abilities like changing tropical weather to winter. Grandis and her hencemen discovered another inhabitant on the island named Ayerton, who was also shipwrecked and tried to consume much of their supplies and buried him in the sand as punishment as they were disguised as monsters. Their monster disguised was short lived when Jean, Nadia, Marie and King appeared on the island and were reunited as they tried to fix the Gratan in four months. As repairs were about finished, the Red Noah begins to manifest itself and the landscape surrounding it begins to sink into the ocean. Once the Gratan was ready for lift off everyone managed to locate and save Jean and Nadia from a final cataclysm as they venture to Africa, where they hope to Nadia's homeland.
Their new adventure it a snag one night when Gargoyle's aircraft followed them. When the enemy aircraft shot the Gratan, it caused another hole in the balloon as it spiraled and crash landed to Africa. At first that they were captured by a native tribe but were soon set free and became friends with the natives. Their new alliance proved victorious against Gonzalez, who was causing trouble with the natives and later kidnapped King, Nadia, and Grandis. Afterwards, they traveled onward towards Tartessos, the country of Nadia's suppose homeland. When they reached a lake, Nadia begins to act strangely as she is slightly possessed by the Blue Water. While she was possessed, she managed to open an underwater passage from the lake and other underground doorways that lead to the ruin city of Tartessos where she explains her true origins about herself and her heritage from both Atlantis and the Neo Atlanteans upon her discovery from Red Noah. Despite the fact that she was not of this Earth, everyone still accepted Nadia because they cared for her.
Their happiness was soon short lived when Gargoyle and the Neo Atlanteans arrived via aircraft where they discovered Nadia. She sacrificed herself to become held hostage in order spare the lives of her friends. Gargoyle soon betrayed Nadia's trust and tried to kill them all. As everyone tried to escape the deadly assault, everyone was soon rescued from Electra, who she and the rest of the Nautilus Crew were revealed to be alive. As everyone regrouped with the Nautilus crew in a space ship to take arms against Gargoyle, they soon discover that he plans to rule the Earth and place humanity into servitude. As they go into space to confront Gargoyle one last time in space, the Grandis Gang tried to sabotage the force field generator and sacrifice the Gratan to do so. Grandis was soon captured along Hanson and Sanson. Grandis was soon freed by the Nautilus crew after the defeat of Gargoyle and returned to Earth as a badly injured Captain Nemo sacrifices himself to save Grandis and the others. One of Nemo’s last requests was to have Grandis to look after the children based on her relationship with them. She also discovered that Electra was pregnant with Nemo’s child, meaning she won his love.
By 1902, after twelve years since after the defeat of the Neo Atleanteans and the tragic death of Captain Nemo, everyone went there separate ways. A grown-up Marie tells us that she is alive and well, but still looking for a serious and stable love. She's quite popular though with men and is last seen at a golf court surrounded by them. Every man there offers her to use their club and according to Marie, "Grandis is always gallivanting around."
Nadia of the Mysterious Seas
Three years after the defeat of Gargoyle and Neo-Atlantis, a new threat has surfaced bent on bringing the world under his control.