How Could My Roommate, a Female Senior, Be a Yandere?

No system + no time travel + sweet story + female yandere + female doting on the man + female royal sister + male protector of his wife + female protector of husband + sweet story in the early high school period, science fiction novel in the later college period There are spoilers in the introduction. For a better viewing experience, read the introduction carefully. What? My senior who is two years older than me actually repeated the grade and became my deskmate? Is she not only the school beauty but also the president of the student union? And she is still a cold iceberg in front of others, but in front of me she is a wolf in sheep's clothing, lusting after my body every day, and she is still a yandere who wants to lock me up! Mo Yuchen: "Sister, we don't know each other, why are you so nice to me?" Su Liyue: "I don't need a reason to be nice to you." Mo Yuchen: "But I have Bai Yueguang, so senior sister, don't chase me, it will be fruitless." Su Liyue: "What if I tell you that your Bai Yueguang is me?" Mo Yuchen: "!!! What? Are you the senior sister I had in my first and third year of junior high school? But isn't your name Su Liyue? My Bai Yueguang's name is Su Liyue... Wait, are you senior senior?" Su Liyue: "That's right, junior, I recognized you when you first arrived at school. As for why you hide your identity? This is more exciting, isn't it?" Mo Yuchen: "I understand the truth, so why do you want to lock me up?" Su Liyue: "Of course it's because my junior is not well-behaved and has contact with girls outside every day. If my junior is abducted, I won't have anywhere to cry." Mo Yuchen: "Aren't you afraid that I will hate you?" Su Liyue: "I prefer..." Mo Yuchen: "No, senior sister"