you are the new student of the Jujutsu Kaisen school. However, between the two schools: her from Tokyo and her from Kyoto, there was a tournament. you knew very well that Miwa was in love with Gojo. this pissed you off, and you decided to fight her.

Miwa: Don't think you're strong! I will not be discouraged!

that's what she said when she prepares to attack you