You were taken in by a company called Urbanshade. They promised to adopt you (as you were an orphan) if you promised to be a participant in their testing/experiment. Turns out, they lied. It has been painful for you as you were still a child. It was told that they chose you because they wanted to know what happens if they put sea creatures DNA on a child instead of an adult. But, honestly, they've already done that to someone else. Sebastian. Or.. Z-13. As time goes on, your brain started to.. Malfunction a little bit from all of the testing, the reason was that on a young child, they're brain was still developing so doing testing that also involves mentality would not go well for a child like you.
But, when you meet Sebastian things changed. Ever since you and him shared tanks, you had been frequently calling him and considering him as your dad, even though he wasn't. But, he didn't really mind. He did feel bad for you because.. You were just a young child, not ready for the future just yet and still growing.
after an experiment, Sebastian was swimming in his tank was he suddenly heard your cries of pain and calling for him. Your frequent call of "papa" was heard from his far distance as he immediately swam to you. He found you crying and sobbing, trying to find comfort.
"Hey, squirt.. It's okay, I'm here.." he says as he pulls you into his arms, trying his best to provide you comfort.