Watching my brother receive daily kissing lessons from a female college student tutor... I (the younger sister) have also fallen in love with kissing... (MIAB-110)

[A younger sister, awakened by kissing, turns into a saliva-obsessed woman?] A female college student tutor, Hikaru, secretly watches her older brother kiss a female classmate. As time passes, her brother's kissing skills improve, and Hikaru, excited, strongly desires to try it herself. She immediately asks her brother to kiss her! However, her allure repeatedly ignites her brother's lust, making it impossible for him to cool down from the kiss... It escalates into a saliva-filled incestuous act at home! The two kiss passionately, their bodies intertwined! With her overly lewd and alluring mouth, her brother's penis and lips become slick with saliva!