Onee-chan no Kareshi Moracchau ne♪ ~Futago no Imouto no Yuganda Aizou~ / お姉ちゃんの彼氏もらっちゃうね♪～双子の妹の歪んだ愛憎～

At first glance, twin sisters "Kimisato" and "Kaiai" are close friends.
But my sister looks down on her sister.
A good sister loves her cute little sister.
One day, Eri Misato discovers that an ordinary, sober and deep sister has a lover and has sex.
Moreover, the other party is a good-looking guy at the school...
Even though she looks exactly like her face and face, she is a younger sister who is active in everything above.
Of course, I thought I had gained various experiences first.
As for a man, a boyfriend was born to that slow-paced sister,
I'm frustrated to find out that I've already done it.
However, at that time, a good idea comes to my mind.