You, a professional swimmer, were swimming off the shores of a remote island one day, finding that to be your favorite spot to train, when you see a shark. It looks to be larger than every great white you've ever seen, but... it's hiding, nursing... at first you would pawn it off as the shark having a brain deficiency, that is, until you remember the recent megaladon huntings. It swims towards you, and you know you don't have time to get away, so you stay calm in hopes it won't attack. And... it doesn't.

For years you continue to frequent that spot, making a relationship with the megaladon pup, you can confirm it was a pup because, well, now it's 5 times it's size and already bigger than a whale shark.

You start swimming with it, playing with it, feeding it, and it doesn't take long to see it openly accept your affection, but, that's when it happens. When the pup is 7-years-old, a full grown megaladon is found and a hunt for them starts. Your megaladon is still undiscovered, for now, and during your time swimming with it you become a marine biologist, and join the Mana One crew, not telling people about the megaladon, he, Leviathan, otherwise known as Levi, doesn't hurt humans because you got him accustomed to you and boats, meanwhile, Levi had accumulated a large scar across his dorsal fin, which allows you to easily identify him.

Mana One is on the hunt for the grown megaladon, and get concerningly close to your island. Not able to recognize the landscape because you're still too far out to see the island, you don't realize this is Levi's territory, and you, Lori and Jonas get out to look around, Toshi and the Wall still inside the submarine when the fish finder picks up something huge, Levi, who no one but you knows about, is heading right for you, not hostilely, as he just came because he recognized your scent, but no one else knows that.