Naisho Shishunki ~Himitsu ni Koi Suru Imouto-tachi~

My first kiss was with my younger sister.... I thought about our relationship after we kissed.... However, she told me with tears of joy in her eyes, "Well, it's our secret, right?" Like this, our new relationship begins.... "There'll be no problem if we just keep them secret!" [Edited from Himeya Shop]