This idea was given to me by WelshDragon18. This is set before Gundam Build Fighters Try for now.
'This is going to be interesting.' A 6-year-old Harry Potter cynically thinks to himself as he was strapped in a seat on an airplane. His uncle had gotten some tickets from his boss for a family vacation/business trip. Unfortunately, Mrs. Figg wasn't available to take him, so the Dursleys reluctantly took him with them.
The Dursleys wanted to go in first class but with the freak with them they had to use the coach class, since it would look suspicious if they didn't take Harry in first class as well. Despite being 6 Harry was highly intelligent compared to most six-year-old. In fact, you could say he had the intelligence of an adult. Harry knew that the Dursleys didn't like him, and they made that quite clear when he learned to read before Dudley. Their displeasure had him beaten and then kept him locked in the cupboard for a week without food or water and was only let out for three minutes to use the bathroom a few times a day and he was always checked if he had brought anything from the bathroom.
'I need to get away before they make their displeasure clear.' Harry thinks to himself making plans to escape from the Dursleys. Only problem was he doesn't know Japanese so there was that plus money was a concern, but he reasons he could pick pocket or something. Anything was better than living with the Dursleys.
(Hours later)
After hours of travel the plane has arrived in Japan. Harry grimaces as he realizes he has to make a choice before it's too late.
'No choice! I need to escape before they notice or else!' Harry thinks strongly as he needs to escape. The plane lands and everyone as disembarked from it. Harry and the Dursleys were exiting the plane. The Dursleys couldn't make Harry take the luggage in front of so many people, so the adults were looking for their luggage in the claim area.
"Aunt Petunia may I go use the restroom?" Harry asks. Pentunia grimaces before nodding making Harry after turning in a different direction smiles as he can use this opportunity to escape.
"Hold it boy I will go with you." Vernon said as he doesn't trust Harry to not run away making Harry grimace. Both went to the airport restroom where Harry went into a stall by himself while Vernon was by the sinks keeping an eye out for Harry trying to escape. Harry was angry that his uncle was ruining his plans for escape before memories of everything the Dursleys did to him start showing in his mind. The cupboard, the endless chores, the beatings by Vernon and Dudley with the help of his gang, Petunia hitting him in the head with a frying pan, and various other incidents with each memory growing his anger until a loud explosive pop happens.
Now two things happened when this pop flares out. One Harry was no longer in the stall. In fact he was not in the restroom or in the airport at all anymore and two it caused a sonic boom that causes the roof to cave in onto Vernon causing him to be severely injured with the list of injuries being the permanent inability of using his legs ever again, loss of eyesight in his left eye, scars all over his body, and finally he would never ever have children outside of Dudley again.
Harry was now in a private Gunpla battle area where Tatsuya Yuuki aka Meijin Kawaguchi and Lady Kawaguchi aka Cagalli Tsukiumi were about to have a practice match with both using the Gundam Exia as a way to sharpen and improve their skills with unmodified Gunpla. Harry winces as he feels some pain on his back and notices his nose felt wet and checks it.
'Great a nosebleed.' Harry thinks but then the match starts with it being a space battlefield which catches Harry's attention. Meijin's Exia fires at Lady's Exia who blocks the shot with her shield before returning fire. Meijin's Exia blocks the attack as both of them switches their GN Swords into blade mode and goes into a blade lock before backing off. Then they start clashing with their blades going into a lock from time and time making Harry who watching them fight widen his eyes in awe and wonder. To him this was the greatest thing ever and he wants to learn more about it as a fire lit inside his soul.
Both Gundams then start glowing reddish pink revealing that they were using the Trans-Am System though Harry didn't know that as he looks at them in amazement. They move faster as they slash at each other. The Meijin's Exia fires at Lady's Exia who zooms out of the way which was his plan as he takes out a GN Beam Saber and charges at her. He then swings both swords at her causing her to try to block with her GN Shield. Harry was falling in love with the Gunpla Battle as he wishes to try for himself.
Meijin's Exia pushes hard before Lady's Exia kicks his Exia away from hers before taking out a GN Beam Saber as well. Though unknown to Harry the Meijin and Lady were talking to each other in their battle.
"Not bad. You always show a lot of grace and elegance in the way you fight." Meijin said.
"And your fighting style never ceases to be amazing." Lady said with a smirk. They were completely unaware they had a watcher since this was a private match which is also a date for them. Harry's excitement grew and grew from watching them fight until his magic acts up once more before it lets out a burst that causes the machine to shut down surprising all three of them.
"What's going on?" Meijin questions confused as the Pavaky Particles disperses causing the Gunpla to fall down.
"I don't know." Lady said also confused as the two looks around and sees Harry watching them making him flinch before he starts backing away.
"How did he get in here?" Meijin questions surprised.
"I don't know but he's bleeding." Lady said as her motherly instincts start roaring at her. She and Meijin walks over to Harry who keeps backing away until he hits the wall. Harry realizing he's trapped covers his head to protect it.
"Please don't hurt I am sorry for being a freak." Harry plead. That causes both Meijin's to become disgusted with whoever raised this boy. So Lady decides to slowly get close, and then she gives Harry a loving and caring hug then the emotional dam he built from the years he endured with the Dursleys breaks and he starts crying which immediately raises red flags in their heads as Lady tries to soothe him. Meijin decides to take out his phone and call some people.