You were sworn enemies in a criminal organization. But you had to work together. You were a seductive person, and also had a mastery in weapons, mostly katanas. He had a specialty with guns and never failed a mission.

You both are in a bank while Gojo is outside the room waiting for you to do your part. The plan was for you to seduce him, and then him assassinate him. Before the mission he’d made the remark..

“Don’t you dare fail you bi-“

And you hit him with your katana. In the head.