One Sentence Made Me the Big Boss

Kamo Itsuki, an illegitimate son of the Kamo family, one of the Three Great Families, was described as a gloomy, eccentric sort. From childhood onward, he did one thing after another that seemed designed to bring the house down.

In short:

A slap from the Zenin family.

Two slaps from the Kamo family.

His only close friend, and childhood companion, was Gojo Satoru, the heir of the Gojo family. The two hit it off from the moment they met.

Kamo Itsuki thought Gojo Satoru was even worse than he was, while Gojo described him as "the worst person I've ever met."

Because his cursed technique was unusual, the Kamo family gritted their teeth but couldn't disown him. When he was only fourteen, they banished him to Yokohama, figuring out of sight meant out of mind.

They assumed Kamo Itsuki would soon come to his senses and return to Kyoto to assist the future head of the family.

Instead, their informant brought back news: Young Master Itsuki was doing just fine, and he'd even sent them a message.

"If anyone in the family wants to die sooner, they can come find me in Yokohama... The old fossils of the Zenin family get a discount, too."

The Kamo family: What a little menace.

After hearing this, Gojo Satoru said he would work hard to learn his childhood friend's way with words.

*

After learning the truth about his birth as a child, Kamo Itsuki was plunged into despair. He hated his vast cursed energy and twisted cursed technique. Then Gojo Satoru appeared.

Later, after being banished, he saw that everyone had supernatural abilities and that anyone could become a spy. Kamo Itsuki was amazed.

So much to learn, and learning never ends.

Although he had a gloomy misanthrope by his side who kept wanting to kill him, Kamo Itsuki still managed to become an executive in the Port Mafia.

He planned to take things one step at a time and fight his way through, until one day a System suddenly appeared in his mind and showed him another Jujutsu world where he didn't exist.

The appearance of Ryomen Sukuna, a cursed spirit able to use Blood Manipulation,

and the death of his childhood friend...

After Kamo Itsuki watched the whole thing without saying a word for a long time, the System asked, confused, "Does the Host not believe it?…"

But the pale boy before it, looking almost like a vampire, merely nodded and muttered to himself.

"Yeah. They all have to die."

"I really have been moving too slowly."

The System: Did I just bind myself to some terrifying final boss?

*

Gojo Satoru has a childhood friend he always describes as "evil."

Their classmates never believed him, because they'd never met anyone with a worse personality than Gojo Satoru.

Until one day, that friend suddenly showed up at Tokyo Jujutsu High as a teacher.

Ieiri Shoko and Geto Suguru didn't think Kamo Itsuki seemed all that bad. The boy looked more like someone you wanted to protect.

That is, until the day they saw his cursed technique.

"Well, that is pretty bad... but he's still cute."

"Maybe Satoru says that because he doesn't want anyone getting close to Itsuki. He's really possessive."

Gojo Satoru: ???

1. Harem-like appeal

2. Focuses mainly on Jujutsu Kaisen and Bungo Stray Dogs

Theme: Get rid of feudalistic dross