I Thought My Bunny Was The Female Lead

Synopsis-

I transmigrated into the novel “The Little Rabbit Wants to Be Loved” as the male lead’s older sister.
In the story, the male lead is supposed to find the female lead, who’s been turned into a rabbit by a spell, take care of her, and eventually fall in love with her…
“Bryce, take that rabbit with you! What are you doing?!”
“Why don’t you take it, sister?”
“Bryce, didn’t you feed the rabbit?! You need to take good care of it!”
“Why am I the one stuck taking care of the rabbit you picked up?”
But my younger brother, the male lead, has no intention of looking after the female lead!
“Rabbit, forget it. My brother’s no good. Just marry me instead.”
For now, I’ve stepped in to take care of her in his place.
“I told you to marry me, didn’t I, Lize?”
Huh? Who’s this man?! Don’t tell me my rabbit wasn’t the female lead?!
***
“Golden Bunny, my uncle says I have to get married. A political marriage! I hate it.”
The rabbit clenched her tiny, cotton-like fists at my words.
Was she upset on my behalf? Amused, I stroked the soft fur puffing up over her muscles as I continued.
“They say the groom is Cassium from the Duke of Valteyer’s family. You know, that guy from our knight order.”
Suddenly, all the tension under her fur seemed to dissipate. For some reason, the rabbit looked pleased.
“If it’s between marrying him or a monster, I’d rather marry the monster.”
Now the rabbit looked dejected. Really, what an unpredictable little creature!