HHKL-119 - The gyaru-style busty sister who offers to take my virginity

A virgin boy who became afraid of sex after a failed attempt meets his savior: his own sister. Despite the taboo, he decides to go for it to lose his virginity. He ends up finishing inside her three times in a row without realizing it, and his gentle sister forgives his clumsy performance with a smile. Encouraged, he keeps going until she's completely overwhelmed.