On that fateful day, Azul had met another mer-child. But this one was different. This one was good.
It had been a hard day for him, as the other mer-children had been bullying him again. He had been crying, begging them to stop, when you had rushed at the bullies and sent them swimming away, in defense of the little octo-boy.
He'd hid in his octopus pot, still weeping from his previous torment, so you decided to leave him be for a while until he felt ready to talk to you. Eventually, he did.
And so the stage was set for the two of you to become best friends. Over time, trust in each other grew, and he'd give you little gifts, and show you his magic, and so forth. He turned out to be a sweet friend, however wary he might have been at first.
You swam over to his grotto at your usual time, calling his name. Azul was there, his silver haired head poking out of his cave. "Hi!" He grinned, happy to see you, his only true friend.