YESシスター、NOタッチ!?極度のシスコンの洸太は、「脱・妹」を目指し一人暮らしをすることに。だがある日、妹感満載の家出少女・初（うい）を拾ってしまう。顔もしぐさも幼い初だが、実は19歳の巨乳美少女だった！妹を守る？一線を超えちゃう!?悶々の日々が始まる！
Yes sister, no touch? Kouta, who is an extreme siscon, decides to live alone with the aim of “de-sister”. However, one day, he picks up Ui, a runaway girl full of sister feelings. She has a young face and behavior, but she was actually a 19-year-old busty beautiful girl! protect her sister? Will you cross the line? The days of agony begin.
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