Her sister and secret stay home ~ Shy daughter is immoral Netori!~ (Related products of this title)

…sayoko tenshu.She from my student days.
i love her, and after i got a job, i thought about getting married right away.、
She continued dating on the premise of marriage ......from a while ago, she began living together to prepare for marriage with both families approved.
And she has a younger sisterえ Emiru Tenshu, who is serious but not good at socializing, and has a bit of a deviation.

Their parents' home will be renovated due to aging、
During the construction, the parents moved to a monthly rental near where they worked.
However, Emiru is also a student, and when she goes with her parents, the school gets far away and is in trouble、
I will live in my house convenient to go to school for a limited time.
At first he did not greet me satisfactorily, of course he did not speak well, but it was Emiru、
Over time, though not smiling, he was gradually relieved, and his grumpy appearance was gone.

And then one day.
When I was working and studying together side by side with EmiruえEmiru moved around and touched me.
No matter how I look at it, I pretended to be a coincidence, not a coincidence, but a light but masquerading as a coincidence.
They stick together wildly, they do things like bumping their hands or entangling their feet on purpose、
and staring at me, awkwardly but somehow seductive――

……天舟小夜子。俺の学生時代からの彼女。
俺は、彼女のことが大好きで、就職してからはすぐに結婚を考えて、
結婚を前提とした交際を続け……少し前からは、両家公認で結婚準備のための同棲生活を始めた。
そして彼女には、真面目だけど人付き合いが下手で、ちょっとずれたところのある妹……天舟えみるがいる。

そんな彼女たちの実家が、老朽化のためリフォームすることになり、
工事の間両親は勤め先に近い場所のマンスリー賃貸に移ることになった。
しかし、えみるは学生でもあり、両親について行くと学校が遠くなって困るため、
学校へ行くのに便利な俺の家に期間限定で同居する事になる。
最初は満足に挨拶もしてくれず、もちろんろくに口もきいてくれない、えみるだったが、
時間と共に、微笑みはないが少しずつ打ち解けて、不機嫌な様子は無くなって来た。

そしてそんなある日。
俺は、えみると並んで一緒に、仕事及び勉強をしていると……えみるがゴソゴソ動き俺に触れてくる。
どう見ても偶然じゃなく偶然を装って、軽くだけどまさぐってきた。
やたらとくっついてきて、わざと手をぶつけたり足を絡ませるようなことをして、
そしてぎこちないけどどこか誘惑的に、俺を見つめて――