Problematic Little Sister Fell In Love With Me

My old man pointed to the flower-like woman and said, "Call her mother from now on." He then pointed to a flower-bud-like girl and said, "This is your little sister."My sister is not cute.She is arrogant, taciturn, and weird, but she knows how to please our parents.She is two-faced and deceitful, but it seems like she only treats me that way.I care for her, try to please her as much as I could, but she still dislikes me.Until one day, I found out her secret, our relationship begins to get a little bit weird...