Japan, 21st Century.
Our story begins with two "normal" teenagers called Hajime Hinata and Natsumi Kuzuryuu.
The two were Reserve Course students at Hope's Peak Academy, a prestigious high school where all of the Main Course student body are composed by the most talentous high school students from the entire planet, the "Super High School Level" students.
Hajime and Natsumi admired Hope's Peak Main Course and its talentous students, so much that they both wished to have talent and join the Main Course.
Hajime, a young man with slightly spikey brown hair with an ahoge and yellowish eyes, wanted to join the Main Course so that he can be with his (and probably only) best friend, Chiaki Nanami, a student from Class 77-B and granted with the title of "Super High School Level Gamer". However, he starting to give up his dream.
Natsumi, a girl with long blonde hair and grayish-olive eyes, is the younger sister of the heir of the Kuzuryuu Clan, Fuyuhiko, known at Hope's Peak as the "Super High School Level Yakuza". The girl, since she wants to be considered worthy of being Fuyuhiko's sister, is very determinated to join the Main Course because she claims that she has talent and that her talent is the "Super High School Level Little Sister" (even if it isn't a real talent, as Hajime also commented)
The two, even if Natsumi was too much arrogant for Hajime's taste, became friends 'cause of their ambitions.
The two at school were nearly always togheter, so much that everyone in their class thought they were dating, something that the two friends would immediately deny.
But, in reality, the two actually thought more than once if they were in love with eachother.
For Hajime, Natsumi had some good looks and can be nice if you know her well but, her arrogant and rude attitude towards the others and him and the fact she's the daughter of a Yakuza act as a deterrent.
For Natsumi, Hajime was an average boy with weird hair and pupils who gives up his dream easily but, she admits that she appreciates his kindness and patience with her, even if she was rude. She also liked Hajime's sass, which made her laugh more than once.
In order to join the Main Course along with her "partner in crime", the Yakuza Princess had the idea to make "disappear" two Main Course students so that there could be two vacant places for her and Hajime.
One of those "future vacant" students was Mahiru Koizumi, the Super High School Level Photographer.
Mahiru had a friend who is, unfortunately, Hajime and Natsumi's classmate.
Her name was Sato, and wanted to defend Mahiru from Natsumi.
But, well, let's say she had some rather extreme methods of "protection".
One of those starts with an "M" and it ends with "urder".
One day, at the end of the lessons. Hajime asked Natsumi if it was okay to wait for her at the exit. the Yakuza Princess said that he could easily go home without her, because she'll be fine and it's not like she's her boyfriend or something.
Hajime left the school but, since he had a bad feeling, the boy decided to remain nearby.
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Natsumi arrived in the Music Room and saw Sato, who seemed rather...off.
"So, you invited me to talk. What do you want?" the Yakuza Princess spoke.
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"...As I said in the invite, I'm going to end this fight here." Sato said, while locking the door without getting noticed. "You....You...."
"Huh? What, did you got hiccups?" Natsumi asked, smug.
But, all of sudden, that smug disappeared when the blonde girl noticed that something was, in fact, wrong with Sato.
"Y-Y-Y-Y-Y-Y-Y-Y-Y-Y-Y-YOU"
"Oi, T-The hell is wrong with you..." Natsumi started to feel scared.
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Meanwhile, Hajime was still waiting for his crush friend at the entrance.
"It's been a lot of time since the lessons finished. Is she okay?" He thought, worried. "Maybe I should go inside...?"
His train of thoughts was interrupted when he saw a mysterious tall and skinny young man analyzing things with a bizarre and futuristic tool.
That person looked like he had the same age as Hajime. He had white messy hair and was wearing Hope's Peak Academy's uniform.
"Pardon me!" He spoke to the brown-haired boy. The stranger had an asthmatic voice.
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"Did you noticed something weird in this place by any chance?" he asked.
"Huh...No? What do you mean, and who are you-"
"My name is not important at the moment,especially for trash like me. You said you didn't noticed anything suspicious, right-"
The white-haired stranger was interrupted by a scream and his futuristic tool started to make a sound, like it was an alarm.
Hajime recognised the voice that just screamed in terror: It was Natsumi.
"What the?! That was Natsumi's voice! I should go check her!" the boy thought.
"Hey, what's your name?" the white-haired boy asked.
"Huh, Hajime Hinata."
"Do you know the girl that just screamed?"
"Yes, her name's Natsumi. She's my friend."
"Well, Hajime. If my calculations are correct, your friend is going to die if we don't move." the white-haired boy said.
"Wha-"
Hajime couldn't even end the phrase at the mysterious young boy grabbed him by the hand and ran towards the school.
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The two arrived in the music room and a monstrosity that was going to eat Natsumi, who fainted.
Hajime was petrified by the terror and illogicality of the situation, but the white-haired stranger was not. He used his tool to create waves that distracted the monster.
"Huh, she's still alive, how lucky!" he said. "Hajime, take your friend and run away. I'll deal with this."
"Wait! What about you? How can you deal with this?!" Hajike asked, worried about the kind stranger's safety.
"Oh, don't worry. Even if I die, no one would miss a trash like me. However, I will survive." The stranger responded.
"But how?! I mean, you seem to have dealt with things like this. Who are you?" Hajime asked.
"If you care so much, well...I am The Doctor. Pleasured to be meeting you." The Doctor introduced himself. "Now go, I'll deal with this and you'll never see me again."
Hajime obeyed and left.
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It's been a week since Hajime had an encounter with that boy called "The Doctor". He constantly thinked about the identity of this guy. By looking at his outfit, he presumed that he was a Main Course Student, but unfortunately the access to the Main Building was denied for Reserve Course students.
However, Hajime was still determinated to find more about this mysterious young man.
One day, Hajime and Natsumi, now fully recovered after the incident were hanging out near the courtyard until they saw a mysterious British blue police box.
"Hey, Natsumi." Hajime said. "Why is there a British police box here in Japan?"
"Do I look like I know the reason?" Natsumi said. "Let's go check it."
The two went inside the police box and their eyes widened the moment they saw that the inside was too much big to be in a police box.
"What the fuck...?" Natsumi said.
"Are we...hallucinating?" Hajime left the box and re-entered in. "No, we aren't hallucinating...It's bigger on the inside than on the outside!"
"That's because it's trans-dimensional." the asthmatic voice of a young man, very familiar to Hajime, spoke.
It was The Doctor, now wearing a green sweatshirt and a white shirt, instead of Hope's Peak Main Course's uniform.
"Hello, Hajime." he said.
"Wait...Aren't you one of my brother's classmates? You're...Nagito, or something." Natsumi said.
"Oh, no no no! Nagito Komaeda, The Super High School Level Lucky Student, is just my fake identity. I am The Doctor, the Super High School Level Time Lord, if you might say."
"Doctor...Who? Also, SHSL what?" Hajime asked, confused.
"Oh, it's just The Doctor. And yes, I am the SHSL Time Lord. This place is my time travel machine, the "Time And Relative Dimension In Space" or "TARDIS"." The Doctor said.
"Did you said...Time travel?" Hajime said.
"Yes, I did." The Doctor responded.
"Tch, bullshit. Like something like this could exists in the real world." Natsumi commented, skeptical about what "Nagito" said.
"So, you think that I'm a liar, huh? Well then, how about a demostration?"
The Doctor started to operate on the console of the TARDIS.
Slowly, the TARDIS disappeared and in started travel through time and space.
<-------To Be Continued---------