Dekakute Ecchi na Ore no Ane / デカくてエッチな俺の姉

The protagonist, Segawa Shunsuke, is much lower than average, which makes him very worried as a student boy.
Living separately from the parental home, at present, together with other guys, the students lived in a university dormitory, however ...
This spring break, he received an invitation from his home and returned home for the first time in 10 years.

After some time, Shunsuke waits for time and arrives home, where in his memoirs his three older sisters always remained overgrown!
Taking custody of Shunsuke too close to her heart, Asaka's elder sister met her younger brother after a long separation, with a wide smile on her face squeezed him in an embrace.
Almost strangling him with her huge breasts, in the end she took him under her guardianship. To the question, for what reason in his own house ...
"Well ... sisters want you to give them sperm to drink ..."
In addition, he heard that sisters have acute bouts of sexual desire, for an unknown reason, symptoms of this disease occur. As a cure for these attacks, they require sperm, they claim.
After hearing this crazy explanation, Shunsuke did not believe it, "Can the little sisters have such a thing!" and was about to leave the house.
However, at this time, the second daughter Tsukino arrived in time, locking the front doors in the hallway and all the windows with keys!
The third daughter, Yuuki, took part in this, who successfully pulled off her pants from the futile attempts at resistance to Shunsuke!? ...

Little brother surrounded by tall sisters during the morning of the day and evening, under the same roof during the day is milked with sperm, sex life under house arrest!
As a result, Shunsuke will have to cure the illness of the sisters, will he be able to safely return to a calm everyday life!? ...