Ore no Imouto wa Kyou kara Do S -O Onii-chan Nanka Atashi no Pet ni Shiteyarun Dakara | 俺の妹は今日からドＳ ～お、お兄ちゃんなんか、あたしのペットにしてやるんだからっ～

Younger sister's name is Aina and elder brother's name is Haruki. From general people good brother and sister, two people with a close relation, the relation that does fellatio very usual on a daily basis. But Haruki was not completely satisfied. He when it is scolded by woman or abused, it comes considerably shivering, he is a "Masochist".

Secretly to his hobby alone one day "Don't Strike AV"" was seen. "I want to come while being teased like this to Aina..." Before one is aware when masturbating thinking so, next to him was Aina...