A Seven Days Girl

By: Tsuki no Shijima

Summary: Hiro screams loudly one morning, terrified to see that he has changed into a "girl". Now, he must tries to spend his time as a girl until God-knows-when while his older brother and friends are trying to solve this problem.

Inspired from the story of "Girls Just Wanna Have Fun" by SaturnXK.

Disclaimer: I don't own Big Hero 6.

Warning: Beware of typos and bad grammar. English is NOT my main language. I have this bad habit of not realizing my mistakes on my stories until days or even months after publishing the story.

-oOo-

Day 1

It was a really nice Thursday morning. The weather of September. It felt really nice that made Tadashi wanted to sleep all day underneath his blanket. He was enjoying his time in the dreamland until a bloody scream assaulted his ears.

"AAAAAAAAARRRRRRGGGGGGHHHHHHHHHH!"

Tadashi jolted up and leaped out from his bed, trying to see what happened. He was stopped when he saw a cute girl, with black long hair, chubby cheeks, and glossy lips, sitting on his brother's bed. He didn't remember if he had ever seen the girl before. And wondering if she was Hiro's friend, or girlfriend? But, when did she come?

He didn't see Hiro, so he cautiously walked to the bathroom without taking his eyes off of the mysterious girl. He knocked on the bathroom door, "Uumm, Hiro? Did you bring your friend here? Or is she your girlfriend?"

No answer from inside the bathroom, instead, the girl answered him, "Dashi, it's me. Hiro." She looked terrified. Tadashi only stared at him, shocked. That girl was Hiro? His baby brother? What the heck?!

"Oh my God, Dashi! I'm a girl! I changed into a girl! What happened to me?!" Hiro got up from his bed and paced frantically.

Tadashi only stared at hi—her in dumbfound. He didn't believe on what he was seeing right now. Hiro, his baby brother, was not a boy anymore. He was a girl now. He changed into a girl, in one night. Did he do something wrong last night?

"Dashi! Stop staring at me like that! Help me out!" Hiro yelled at him, with a feminine voice.

"Uuh, okay?" Tadashi rubbed his back neck, "What did you do last night?"

Hiro raised hi—her eyebrow, "What do you mean?"

"You know, the thing you did last night, or maybe even before that."

He—she was trying to recall on what she did yesterday that might possibly changed him into a girl overnight. "Nothing. I only played the game you bought last week all day."

"Anything else?" Hiro shook her head. Tadashi sighed. What in the world happened to his baby brother? Another sigh escaped from Tadashi, "Luckily, aunt Cass is still in Grandma's house until tomorrow. So at least, we have two days to figure out what has happened to you." He looked at her, "And solve the problem."

She nodded, unsure of what to do at the moment. "Anyway, I'll go take a bath now. I have a class in an hour," Tadashi said, as he looked at the clock.

After he finished his bath, Tadashi put his books into his brown satchel and walked downstairs to eat his breakfast. While eating his breakfast, he saw how worried Hiro was, being a girl and all. It was all written on hi—her face. He smiled and ruffled her hair, "Don't worry, knucklehead. I'm here for you. We'll figure it out and change you back soon."

Hiro looked up to him and smiled weakly. "Alright. I'm off to school now. Just text me, or even call me, if something bad happen. Or if you need anything. Okay?" Hiro just nodded. Tadashi hesitated at first, not wanting to leave Hiro all alone. But he needed to go, so he finally off to SFIT.

-oOo-

A few hours later, Tadashi just finished his last class when he received a text from Hiro.

Baby Bro: Hey, Dashi.

Tadashi: Hm?

Baby Bro: Can you help me with something?

Tadashi arrived at his private lab. He sat on a stool nearby and replied Hiro's text.

Tadashi: Sure. What is it?

He was wondering on what Hiro needed right now.

Baby Bro: Can you borrow some bras for me?

He was so damn shocked that even made him fell off from the stool, "WHAT?!" He was blushing, feeling a bit embarrassed. 'There is NO WAY I dare to do that!'

Tadashi: Hiro, are you serious?! People might think I'm a pervert!

Baby Bro: Dude! It's just for a few days until I change back to normal! Besides, my front is not feeling comfortable right now.

Tadashi: What front?

Baby Bro: *Face-palmed emoticon* MY FRONT! Don't you dare make me say the word!

He paused for a while. Trying to figure out what Hiro meant by 'hi- *cough* her front'. It took him a quite some time before he realized what 'her front' meant. He was once again blushing.

He slumped down, covering his flustered face with his hands. 'Oh my God! Why am I such an idiot!?' he screamed in his mind.

Tadashi: Ooh! O-okay?

Baby Bro: Okay for what? Are you going to help me or should I buy some by myself, like, right now?

Tadashi: Don't you dare go out like that! Especially ALONE without me!

Baby Bro: So?

Tadashi: Fine! I'll try to ask for a help.

Tadashi sighed in frustration. To whom he should ask for help? Then he remembered Honey and Gogo. Maybe, just maybe, they could help him.

He went out from his lab, searching for the girls. He found the gang talking in Fred's side of room. "Uumm, guys, can you help me with something? Especially Gogo and Honey?" he asked. They tilted their heads in confusion. "Sure," they said in unison. Tadashi instructed them to follow him to his lab.

Once they were in Tadashi's lab, they saw how nervous he looked like. And he was fidgeting, too. Something was definitely wrong.

"Uuum, Honey, Gogo, can you help me with something?"

"Sure!"

"Yeah, sure."

Tadashi gathered all his courage and then blurted out the words, "Can I borrow your bras?"

Silence.

Silence.

Silence.

And then, Tadashi's vision suddenly turned black.

-oOo-

After the episode where Tadashi got a punch on his face from Gogo, lying unconscious on the floor for ten minutes after her punch, and he woke up to earn some unreadable looks on his friend's faces, Tadashi felt like a hawk was eyeing him as a prey. And he knew too well where that came from.

"I never knew that you're actually a pervert, Hamada," Gogo said.

"What?! No! It's not like that!"

"Then what is it?" Honey asked.

"Yeah, dude. Why do you want to borrow their bras? Are you trying to do a cross-dressing thing?" Fred asked.

"Uh, I don't think Tadashi is actually into a cross-dressing thing," Wasabi said.

"Guys! No! They're not for me. They're for Hiro," Tadashi stated.

Silence, again.

"So, now you're trying to accuse your own younger brother?" Gogo asked again, narrowing her eyes.

"No! Of course, not!"

"Then explain!" Gogo demanded him. Tadashi sighed. So, he tried his best to explain Hiro's situation to them. After a few minutes of explanation, Honey's face was beaming.

"Honey, what's with that face?" Wasabi asked.

"I really, really, want to see Hiro right now!"

They raised their eyebrow. "Well, I don't think we can lend you our bras, because it's not good for her healthiness. So we need to buy some in an underwear shop nearby. And, I could lend her some of my old clothes for her to use. Aaaww! I'm sure she will look cute in those dresses!" Honey said with enthusiast.

Fred put his elbow on Tadashi's shoulder, "I think it sounds great. What about you, dude? Want to see her in dresses?" Tadashi bit his lower lip.

-oOo-

"I'm home! Hiro?"

Hiro heard Tadashi's voice from downstairs. She went down while hugging a pillow. "Oh, so you're back. And, bringing the gang, too?"

"Hiiiirrrooooo, I've brought you some clothes! Oh and the bras you need, too!" Honey said, gleefully.

"O…kay?" she raised her eyebrow.

Tadashi saw the pillow Hiro was hugging, confused. "Hiro, why are you hugging a pillow?" He asked. Then, he earned an incredulous look from Hiro and the gang's faces.

"Did you just ask that?! Seriously?!" Hiro asked, not believing on Tadashi's question.

"What?" Tadashi felt dumbfound.

"Tadashi, did you just expect your brother, I mean, sister, to come down with something jiggling on her chest?" Gogo asked, still with an incredulous look on her face. Hiro blushed after hearing the 'jiggling' part.

He slumped down and covered his face in embarrassment, again, for being so slow to notice those kinds of things. The others just shook their heads. "Not again!" he said, still feeling embarrassed.

-oOo-

After giving Hiro the clothes and taught her on how to wear a bra, Gogo and Honey came down to the living room. Wasabi was sipping on his iced-tea, while Fred was eating a donut. Tadashi? Well, he's still hiding his face.

"Don't feel embarrassed too much, Tadashi," Honey said.

"Yeah, you didn't know because you never had a sister," Fred said.

He looked up to his friends, "But still, why am I being really slow when it's about these kinds of things?!"

Twack!

"Woman up!"

"I think I will be like that too, if I were in Tadashi's position," Wasabi stated.

They heard the sound of footsteps coming down from the stairs. Hiro appeared in front of them, wearing a pink pyjama dress with bear motif on it. She blushed, and feeling uncomfortable with wearing a dress. Honey squealed and immediately taking pictures of Hiro with her phone. While the others just stared at her, mouths gaped open.

"Stop staring at me like that!" Hiro protested at their stares.

Gogo popped her gum and said, "You actually look good in dress."

Hiro looked at her, horrified, "You're not serious with that, right?"

They were debating about how pretty, or cute she was with dress. Even Honey and Gogo were planning on taking her shopping. Wasabi and Fred just chuckled at Hiro's funny reactions on the plan. While Tadashi just stood there, looking at Hiro, with jaw opened.

Hiro noticed this, "Why are you looking at me like that?"

He sighed hopelessly, "I know I'm not supposed to say this. But, if you're not my sibling, you're actually my type."

Another silence.

.

.

.

.

.

.

.

.

.

.

.

"I never knew that my older brother is actually a lolicon."

"I'M NOT!"

-oOo-

Author's Note: Sooo, when I was continuing a requested fanfic, I suddenly found this one in my Big Hero 6 Fanfics folder. This should be a humour story with a touch of brotherly fluff (which is not my forte) but I'm not sure with that somehow. I don't know when I will write the second chapter because I'm still intending to finish the requested story and a sequel one-shot first. So, I will just wait and see how the readers are going to react with this one for a while. Now, what do you think? Don't forget to leave a review! Until next time~