Hi there, BH6 fandom, and welcome to the Afterburn universe! This starts post-movie. Please feel free to follow, favourite, and review as the story progresses.

One: Acquainted With the Night

Kage was not someone you would want to bump into in a dark alley.

Unfortunately, that was the only place you would ever bump into him, so there was never much choice in the matter.

It was on a particularly cold and windy night that a man named Yama, fresh from ripping through an underground bot-fighting tournament, took a shortcut through an alleyway to get to his car - and noticed he wasn't alone. A shadow – the figure of a man – shifted out of a darkened niche and stood before him. He was dressed in clothing similar to that of the legendary ninja who once roamed in clans about the land. Assassins most feared, spies never caught, but with a code of honour almost as noble as the samurai they served.

Any wise man would immediately exercise caution around anyone who showed the slightest sign of their skills.

Yama was not a wise man, and after defeating eleven opponents in the last hour and a half, he was feeling decidedly unbeatable. "Did Goku send you? Tell him he's wasting his time, there's no way he's going to fight back to the top of the food chain.'

No reply. That was unusual. By now a fellow gangster's grunt would generally have blustered out a demand, or at least a reply to his taunt.

So… maybe Goku hadn't sent this one. He turned to go, only to find the man once again in his way. 'Who are you?'

The figure still said nothing, but its arm whipped out faster than a striking cobra, and a knockout dart buried itself in Yama's thick neck. As the sedative began to take effect, he heard a low voice whisper, 'My name is Kage. And my masters have need of your… unique... talents.'

Across the other side of town, Hiro Hamada was sitting wrapped in a thick blanket on his windowsill, naming constellations. He was supposed to be working on his latest project, but he just didn't feel like he would make any progress tonight.

Tomorrow would have been his nii-chan's twenty-first birthday.

Even though Tadashi was gone, Hiro was still determined to uphold the little tradition they'd been keeping since the younger boy had turned nine, of staying up until midnight on the eve of their birthdays to watch the stars and count koi-bines in the sky above their neighbourhood. Sometimes, if it was a warm night, they'd climb onto the roof for a better view and trace new constellation shapes to "beta-test" the light-line pens Hiro had invented for a joke, making dragons and faces and mathematical diagrams.

Hiro half-heartedly scribbled a few Pythagorean theorems on the glass of the window next to his calculations for working out the relative area of Orion.

It wasn't the same.

He knew this was the first of many times he would find himself staying up alone, but Hiro had a feeling he wasn't going to get used to it in a hurry.

He looked down to the windowsill, beside where his bare feet peeked out from beneath the blanket, and picked up the paper lantern that sat there.

Hiro reached out for the tall candle that Baymax handed him and lit the lantern wick. The flame began to suffuse the room with a muted light and the small boy gave a quiet huff of amusement as the robot tilted his head, clearly fascinated to see the lantern begin to fill with the heated air. Hiro slid the window open and looked back out at the sky.

A cool breeze ruffled his messy thatch of hair, and as the clock on the desk marked twelve, he released the lantern out into the night where it quickly rose to join the lights in the sky before vanishing from sight.

Happy birthday, Tada-nii. I miss you.

Baymax's voice broke into Hiro's thoughts. 'Hiro, would you like me to play my store of videos now?'

'In a minute, Baymax,' replied the boy as he huddled further into the blanket, his eyes red. The robot blinked slowly, before enfolding his young charge in his marshmallow-like arms and activating his internal heating unit. 'Tadashi is here, Hiro. And so am I.'

A wet sniffle broke free of the bundle on the windowsill, but Hiro smiled – just a little – and returned the hug. 'I know, Baymax. I know.'

'I will play the videos for you now.'

'Okay.'

'This is Tadashi Hamada, and this is the first test of my robotics project…'