I said, turning around. Karen was about to sit down where I had been sitting until now.
“Yes? What is it, Nii-chan?”
She said, looking back at me.
“Could you die for me?”
“Yes, I could die for you. So what do you want?”
… Her answer was as expected, but she still looked so cool… You’re definitely a carbon copy of Kanbaru. Really, if she weren’t my little sister, I think I might have fallen for her. If only she weren’t my little sister…
“Then, could you die for Tsukihi?”
- Nisemonogatari Volume 2 “Tsukihi Phoenix” Chapter 11 (emphasis mine)