1 month later
A dark-haired boy in a baseball cap and a blue jacket fiddled with a micro-screwdriver in one hand, and a mesh of wires in the other. He held two of the wires in a clasp as he tightened it in, securing a connection between the wires and the circuit board. With that last adjustment completed, he fit the circuit board back into a control box and hooked the entire device up to a supercapacitor.
The device wouldn't power on.
He slammed his head into the desk. He had hardly slept the past three days, and he was so close to finally seeing him again...
He saw the green data drive and slid it across the desk towards him; his brother's name was on it. It had only been a couple of months since Tadashi had passed, but it still hurt. His brother was the closest family he had, and he'd been almost like a father to him as well, and now he was gone.
But not everything was lost; looking at the drive reminded Hero of the friends he now had, and the adventures they had shared. And now, he was just a few electrical adjustments away from seeing his best friend of all.
Baymax was created by Tadashi to help people, and that was what Hero planned to help him do - just, not necessarily as a doctor. After his last adventure, he wasn't content to let Baymax go to some medical tech company. No, they were superheroes, them and their friends, and they were certainly needed. After the supers ban, which many countries around the world instituted following the United States, petty criminals were running rampant. San Fransokyo, being an autonomous Territory, had chosen not to ratify the bill, after the heroic actions of a group of young heroes that had saved the life of a tech billionaire; a group of heroes that Hero was a part of.
None of their group actually had superpowers, per se, just really cool technological innovations, so they didn't even know if they could qualify under the supers ban, but just to be safe they only operated in San Fransokyo. Ever since Baymax sacrificed himself, they hadn't been in the public eye very much anyways, as the lovable armoured medical robot was their most valuable asset to the team.
And now, Hero was about to bring him back.
A few hours of work later, he was finally able to power him on. He stood in front of the white robot and said "ow."
The robot's eyes powered on, and it looked at him. "Hello, I am Baymax, your personal healthcare companion."
The boy brought his hand up to his head, in disbelief that he had finally done it; he had brought Baymax back.
"Hello, Hero" The robot stepped forward.
Hero started to laugh, but instead, he ran forward and embraced Baymax.
They would continue to face challenges, but for now, Hero had finally found his friend.