I don't want to be trained by my senior sister!

(Single female lead + transmigration into a book + fantasy + sweet romance)
Fang Xuan transmigrated into a female-oriented angst novel and bound himself to the [Discipline System]—then accidentally set himself as the "discipline object".
Now he's become the female lead Ning Qian's "exclusive"—his daily tasks include, but are not limited to: being fed by his aloof senior sister +0.1, sniffing the blanket +0.1, and being warned by the system for fantasizing about insubordination...
Meanwhile, the senior sister who would one day sacrifice thousands of miles of blood, whose gaze could freeze anyone to death, was blushing as she softly asked, "Tonight... is it going to be like that too...?"
"That's right, please teach me a lesson, senior sister!"
......
But later on, why did my senior sister become more and more obedient?
No, who's training whom here?