"Why do I have to share a bed with him?" eight year old Tadashi Hamada complained. He looked gingerly at his two year old little brother, who was staring up at him with large watery brown eyes and snot running from his nose.

"Hiro said he wanted to sleep with his nii-chan tonight," his mom told him. "Just one night, ok darling?"

Tadashi blew out an annoyed breath of air and his bangs fluttered. Hiro giggled at his nii-chan's antics and for a moment, Tadashi thought his brother was just a little bit cute. But that was gone in a flash when Hiro blew a giant snot bubble.

"Gross, bonehead," he told the kid and climbed into his twin sized bed.

"Ngh! Ngh! Help me, nii-chan," Hiro's squeaky voice floated through the darkness from the other side of the bed.

Tadashi groaned and dragged himself over to the side. "I can't wait until you're older, you big baby. Then you can actually reach the top of the bed yourself." He lifted the kid onto the sheets next to him. He felt Hiro burrow into the blankets like a little gopher and snuggle up to his side. His brother radiated heat like a mini heater. It felt good.

"Good night, nii-chan."

"Go to sleep, Hiro," Tadashi grumbled, but he couldn't keep the smile off his face. Even with the snot bubbles and dependency issues, his little brother was too cute.

Tadashi really missed those days when they had a complete family unit. He missed his mother and father, but he knew it was nothing compared to Hiro who had grown up barely even knowing their parents. He even missed those days when Hiro would call him nii-chan and insist on sleeping with him. Their parents' death was like switch that turned something off between the brothers' relationship. Hiro refused any comfort, saying he was fine. He tried to act older and more mature than he really was. He even graduated high school early, partially because he was smart enough to, but also because he didn't want any human interactions. And Tadashi could only watch helplessly as his baby brother grew more distant and decided if nothing else, he could at least help Hiro achieve his goals.

So imagine his surprise when the night before Hiro's big exposition at the SFIT science fair, his brother came up to him and ask if they could sleep together once more. How many years has it been? he wondered as he scooted over to make room. The twin bed that originally could hold two young kids creaked distressingly under their combined weight, but still valiantly held.

"Good thing you're tall enough now to get up by yourself," Tadashi smirked.

"Shut up, nii-chan," came Hiro's mumbled reply.

Tadashi laid still. How many years has it been since he called him by that? "You...you all right there, kiddo?" He turned onto his side to face Hiro and only saw a shock of black hair peeking out from a mass of blankets. "Hey, you're going to suffocate under there." He pried the blankets off and Hiro's face popped out and glared at him. His eyes were shimmering. "What's wrong?" Tadashi asked, panic seizing his heart. He wanted to wrap her arms around the kid but he held back.

"I-I just really want to get into that school. I want to do cool stuff like you and the others-" He took a shuddering breath. "But what if-"

"Stop," Tadashi commanded and before Hiro could say more, he pulled his brother into a hug. "Stop it. You're psyching yourself out." Hiro made a muffled noise but he ignored him. "You're the smartest bonehead I know. If you can't get in, then I don't think I'm qualified to stay. So you better, alright?"

Hiro looked at him, blinking away the tears. "Geez, way to put on the pressure, nii-chan."

"That's what I'm here for. To push you forward."

They fell asleep that way, two brother's laying on a cramped twin sized bed, limbs tangled together, the older protectively shielding the younger.

Hiro looked at Tadashi's empty bed with blank eyes. A single black baseball cap was set in the middle. That was all that was left of Tadashi after the fire. Tadashi was gone. There would be no more crazy chases down sketchy alleys of San Fransokyo, no more brilliant new tech projects, no more being slung upside down, no more "boneheads", no more "nii-chans", and no more sleeping together on his cramped little bed. Tadashi was gone from Hiro's life, just like their parents had left them twelve years ago. There was nothing meaningful left in his life anymore.

Dust motes danced in the beam of light Aunt Cass had let in before settling down on Tadashi's SFIT cap. Hiro knew that soon dust would cover everything if he didn't do anything, but he couldn't bring himself to remove the hat. With a creaking groan, he got up and began pulling the Japanese paper screen that separated Tadashi's room from his close. He will lock up his memories along with the bed and the hat in that little space. Tadashi was gone. His movements sluggish and slow with grief, Hiro stepped forward and accidently stubbed his toe against the wooden frame of the screen.

"Ow!" he bit out. A whirring noise interrupted his thoughts and he turned to the source. A red box opened up in Tadashi's room and a large balloon creature slowly inflated.

The robot looked at Hiro for a moment before raising its rubber arm in a circular wave of greeting.

"Hello. I am Baymax."

A/N: Yes, I do have a headcanon where Hiro calls Tadashi nii-chan when he's little, and occasionally when he's older when he's most vulnerable. After all, they're half Japanese. To those of you out there who aren't familiar with Japanese terminology, nii-chan is an intimate way that roughly translates to big brother. Can you imagine baby Hiro with his poofy shock of hair running around on tiny legs squeaking, "Big Brother! Big Brother!"? Yes you can.