How Excessive Study Pressure Turned the Sweet, Airheaded Saiki into a Dark and Twisted Person [Anime Crossover]

Some inspiration comes from [Bungou Stray Dogs and Jujutsu Kaisen Watch-Along: I Heard I'm the Villain].

Saiki Miyu is the third son of the Saiki family. Compared with his two older brothers, who have plenty of brains and good looks but could use some work on their social skills, he's a sweet, soft little fool with plenty of charm and social skills but not much intelligence.

Still, with his two reliable and powerful older brothers shielding him from trouble, his life has gone fairly smoothly. The only thing that gives him a headache every day is the pile of exercises that his brothers find super easy, but that leave him floundering.

At last, the academically challenged, hopeless little fool decided that his brief youth wasn't enough to get him through the crushing schoolwork his brothers found so easy. He didn't want to ask them for help, though, since they'd call him an idiot. So he spent three months' worth of pocket money on a huge pile of coffee jelly and offered it to his second brother. “Kusuo-aemon, please, please help me with Big Brother! I want a game console that lets me study in another world where time flows differently. That way I can study and play at the same time. I really can't focus at home T_T”

Kusuo Saiki, coffee jelly in his mouth, looked at his pitiful, foolish younger brother and sighed. In the end, he agreed. He and Kusuke Saiki spent half a day making a game console that connected to another parallel world, one where writers went to war. They set the game to begin several years before the main story, during a period of peace, and placed the starting point outside the Armed Detective Agency. To be safe, they even handwrote a letter for their shrunken-and-regrown little brother to take with him. It would provide the political and cultural knowledge he needed without putting him in too much danger.

But the two older brothers, one off to class and the other off to work, never expected their third brother to run into a space-time vortex. His starting location and time were pushed seven or eight years earlier, dropping him into Yokohama's most dangerous and chaotic era, before the Three-Way Deadlock was established.

Fortunately, Saiki Miyu met the angelic Oda from the start, managed to survive, and awakened a literary talent. Over the next seven or eight years, he made up all the schoolwork he'd fallen behind on and even grew a little taller.

But the good times didn't last. This world turned out to be so cruel, and with time moving too fast and neither brother watching over the console, Saiki Miyu, without his brothers there to protect him, experienced just how brutal the world's malice could be. He'd only been out buying groceries. By the time he returned, five children had been locked in a van, which exploded right before his eyes and Oda Sakunosuke's. Afterward, Oda, his heart broken, gave up his dream of becoming a writer and went to meet his fate with a gun. Miyu couldn't do anything. In the end, he was too late even to reach Oda, arriving only to find a scene of devastation and Oda Sakunosuke's dead body...

Overwhelmed by his emotions, the game forcibly logged him out to ensure his safety. That was the last straw.

He woke up in a breakdown, weeping blood and screaming out his hatred: “Kill them! Aaaaaaaahhhhhhhhhh!!!”

He was a member of the Saiki family, after all. How could he possibly be ordinary?

His supernatural ability awakened. It was called Regret.

As long as he wished, he could return to any point in his life, overwrite everything he regretted, and rewrite his past and future.

P.S. The protagonist always ends up becoming a leader. If you can't accept someone other than Mori becoming the leader of the Port Mafia, or someone other than Tsuna becoming the leader of the Vongola, you can leave. I wrote this story to indulge in the idea of a big-boss growth plan, and because I wanted to write a personality reversal: an innocent, naive person who grows armor-like scales in order to survive, becoming powerful and resilient, with pride in every bone but wounds all over inside. Growth is a process of losing and gaining things. I just gave the protagonist a little privilege so he can pick up what he lost.

P.P.S. I don't see a problem with it. Before Tsuna became the Tenth Vongola Boss, he was a good-for-nothing in every way. At least my protagonist has potential, and his starting setup is better. He also has an even more brutal, heart-wrenching story arc with a cast of schemers before that. Honestly, if the second arc's big boss hadn't been Byakuran, it might not have been as brutal as the first. If he still can't become the Tenth Vongola Boss after all that, he might as well bash his head against a block of tofu and apologize.

Of course, I'm not saying anything bad about Tsuna. I like him a lot. I just want to write a protagonist like this.

P.P.P.S. The first game world is Bungou Stray Dogs, the second is Katekyo Hitman Reborn! (with rising difficulty and growth in the truest, tear-soaked sense), and the third is Detective Conan. That last one is basically about saving people and easing the PTSD left by the first two worlds. It's the story of a sweet, naive fool growing into a dark, inscrutable mastermind.

As for the claim that excessive academic pressure is the cause: that's not exactly wrong. The protagonist's original goal really was just to study. He was simply forced to save the world later.

P.P.P.P.S. If this isn't your thing, don't read it. Click the X in the upper right. Don't make things difficult for me or for yourselves. Let's all get along. Thank you.

Theme: The Saiki family's only academic good-for-nothing is forced to become an all-rounder