Disclaimer: This story was written by an ace person in honor of my amazing aro/ace best friend/little brother back when we were both still figuring out who we were and so I'm keeping it up as something we made as a stepping stone for the two of us :)/p
Tadashi and Hiro were walking down the halls of Ito Ishioka one afternoon after classes when Tadashi noticed a girl passing by giving them a double-take. Honestly, he was used to these sorts of reactions—it was embarrassing, honestly, all of the attention that he unwittingly drew from members of the opposite sex without even trying. But something was different this time—instead of looking at him, the girl was looking at Hiro. Feeling a surge of older-brotherly pride, Tadashi nudges Hiro and whispers, "Hey, otoutu!"

"Mm?" Hiro, who was absorbed in some game on his phone, barely looked up from the screen./p
"Look!" Tadashi purposefully takes the handheld device away from his younger brother and not so gently turns him in the direction of the girl. The young lady smiles shyly and then waves at them. Hiro, for his part, instantly turns red and, without a word, turns away and hurries off down the hallway.

"I think she likes you!" Tadashi says teasingly once he finally catches up with his little bro.

"Um... Yeah, not really interested," Hiro responds, grabbing his phone back from Tadashi and going back to his game.

"All right, well, maybe she isn't 'the one'," Tadashi responds, unwilling to let the subject drop. "But, trust me, I'm sure there are plenty of other girls out there, and I'm know that one's right for you."

"Uh huh—sure…" Hiro keeps tapping away on his screen, quite obviously trying to ignore his older brother at this point.

"How about Mary from biology?" Tadashi asks, still trying to get Hiro's attention. "She asked you to be her lab partner last week, so maybe she's interested!"

Hiro gave a noncommittal grunt before finally saying, "No."

"Okay then, Rachel from Spanish?" Tadashi tries again. "You know that she made that flan specially for you last week, so she's obviously crushing!"

"No!" Hiro groans, looking even more agitated than before.

"Then how about-"

""Tadashi, just NO!" Hiro shouts, finally looking up from his phone and looking slightly red about the face. "I'm-I'm not interested in any girls, all right?"

"..." Tadashi stares at his younger brother for a moment, trying to process this, and then it hits him. "Oh! Gotcha! So, is there a guy, or-"

"No!" Hiro cries, running his fingers through his hair and making it stand up even more than usual. "It's not like that! It's just... I don't know. I just don't really feel that way, like, about anyone."

"Hey, it's okay if you don't yet," Tadashi says, putting an encouraging hand on his shoulder. "You're still young, there's plenty of time-"

"Tadashi, you're not getting it!" Hiro snaps, shrugging off his older brother's arm and turning to face him. "I mean that I don't feel that way and, honestly, I don't think I ever will." He looks down at the floor, suddenly not willing to meet Tadashi's eyes. "I just... I'm happy how I am, y'know? With you and Aunt Cass and Baymax and everyone-I just don't really feel like I need anyone else. And, besides which, I just... I don't think I have it in me. I mean, I've tried liking people before-you don't know how hard I tried to have a crush in high school, just so I could feel normal. But I-I just can't." He finally looks up at the older boy with big, somewhat frightened eyes. "Do you think... Do you think that there's something wrong with me?"

For a moment Tadashi doesn't know what to say. Then he wraps Hiro up into a hug and pulls him in close. "Hiro, there is absolutely NOTHING wrong with you," he says softly. "It's okay not to like girls or even guys. You never have to force yourself to be something that you're not. The important thing right now is that you're happy, and that's all that matters. When—if—there ever comes a day that you ever do find someone special, then great! But you could be aro, or ace, or demi, or any combination of those, and that is amazing too! You are amazing exactly as you are, and nothing is ever going to change that, all right?"

Hiro looks up at his older brother in disbelief for a full minute, and then suddenly nods and hugs him back fiercely. "T-thanks, niisan..."

Tadashi smiles down at his little brother and hugs him a little closer. "Not a problem, otouto." No matter what, he would always stick by and support his little bro, and that was a Hamada guarantee.