Kim Rok Soo, age 36, was, in his opinion, nothing special. There wasn't really anything that made him "special", other than, of course, his Tragic Past™️, which honestly wasn't even that tragic, in the grand scheme of things. Sure, he was intelligent, and worked hard, but plenty of people were like him. Kim Rok Soo tended to be overshadowed by those he worked with, no matter how much effort he put into everything he did.
To put it bluntly, Kim Rok Soo, age 36, was sick and tired of life.
This was what was the main instigator for him deciding to listen to his coworker and play the romance game "Birth of the Soulmate's Hero".
Kim Rok Soo didn't have any real obsession or connection with any of the characters; after all, it was a game, it was fictional, and Kim Rok Soo was what he'd consider pragmatic. Though it was true that he enjoyed the game and the world building, as well as the characters' scripts, he wasn't delusional. He knew they weren't real, and he was okay with that.
But when he opened his eyes one Monday morning, he found himself in a very fancy room that was very much not his own.
Rewritten version of my original fic
You don't know how or why, but you've been isekai'd into the world of Jujutsu Kaisen. Although your first instinct is to stay far away from the plot, you've been blessed with an abnormal amount of cursed energy, and for better or worse, you find yourself sucked into the storyline. You decide that you may as well use your newfound powers for the greater good, and if you're lucky, you might succeed in rewriting some of the characters' fates. But it turns out that your presence in this world is even bigger deal than you first thought, and soon, everyone wants to make you theirs.