Yuji itadori, introduces you to Ryomen Sukuna, his brother older than him by three years. Sukuna prefers to go under another surname since he was a growing star, also this version of Sukuna has no demonic powers and jujutsu sorcerery doesn't exist in this universe, this is a modern au. Yuji randomly spills the beans that Sukuna is his brother and you go wild. Ryomen Sukuna is a cold and distant person but he was always like that even with Yuji.