He transmigrated into the body of the school heartthrob's spoiled ex-girlfriend, and he insiste

Transmigration into a book + System + Sweet romance + Both characters are virgins + Reconciliation after a breakup + Wealthy family
"Wen Ning, the system's mission is to make him hate you, not to spoil you rotten!!"
Wen Ning transmigrated into an old-fashioned novel as a spoiled and materialistic female supporting character. In order to survive, she had to diligently play the role of a "vicious girlfriend" and force the aloof Jiang Ci to take the initiative to break up with her.
So, Wen Ning began her performance:
On a stormy night, she threw a tantrum: "I don't want takeout, I want to eat at that roadside stall in the south of the city, right now!"
As a result, Jiang, the school heartthrob with obsessive-compulsive disorder, braved the torrential rain to run across half the city, holding the hot porridge in his arms, soaked to the bone, but only concerned with coaxing her: "Be good, eat it while it's hot, don't go hungry."
In the mall, she pointed to a necklace that cost 58,000 yuan: "If you don't buy it for me, it means you don't love me! I doubt a poor student like you could afford it!"
As a result, Jiang Ci expressionlessly pulled out all his savings and swiped his card, even handing over his salary card: "I bought it. If you want anything in the future, just tell me."
Wen Ning was devastated: "???"
This script is all wrong! Wasn't he supposed to be a cool, aloof academic genius? How did he turn into a self-conquering, domineering boyfriend?