One day, Mana, a female college student, is asked by her friend's brother to take her virginity at her friend's house. Mana is a kind-hearted girl who is easily persuaded, so she goes along with it and accepts, but her brother is not a virgin and has an extremely strong libido! Mana is made to cum over and over again by his unexpected thrusts and continuous sex. Furthermore, her brother, who is also a virgin and has an extremely strong libido, approaches her and has sex with her, causing her to arch her back and climax repeatedly!