Sukuna is the strongest and invincible Curse King

In the past, when he was still Human, Sukuna met a girl who was Sukuna's only friend, and that girl was the girl Sukuna loved.

But Unfortunately the Girl was killed, the reason is unknown, Then when Sukuna turned into the King of Curses, he met the Reincarnation of the girl, but still, At the end the girl was killed too, and in this time, He met the girl reincarnation again, and now Sukuna is not will repeat the same mistake.