MKON-029 Because of me, my sister ended up having her thighs touched by classmates Kanae Kawahara

When my classmates found out I have an older sister, they came at me with 'Let us touch your sister's thick thighs w' and forced me to make that promise. Bracing myself to be hated by my beloved sister, I told her about it, but she said 'Sure'. What the hell!? Let random kids younger than herself freely touch her thighs? That's not okay! Honestly, I thought she'd refuse, but my sister's sense of chastity was surprisingly lacking, and I was a bit disappointed...