あらすじ
Yuka has always loved her childhood friend, Kota—and recently, the two finally became a couple. Two months into dating, Yuka goes to Kota’s house to have their first intimate experience together. But since it’s the first time for both of them, things don’t go well. As Yuka struggles with frustration and insecurity, the one who appears before her is… Kota’s younger sister. “Become my ideal girl.” A boyfriend, his girlfriend, and his little sister. An irresistibly sensual, yet unbearably immoral three-way entanglement is about to begin.