Who Kissed Me When My Roommate Was Killed by a Werewolf?

[Two heroines] + [Suspense? ＋Sand Sculpture Here's the thing. On my birthday, I stopped drinking. I felt like someone was sneaking up on me - mouth to mouth. When I woke up the next day, my lips were swollen. But here's the problem: The only people present that day were my four college roommates. Roommate No. 1 Song Wanrou: She is as gentle as a dummy, and looks affectionate to everyone. She is the "mom" of our dormitory. But she has a boyfriend, I even saw it with my own eyes... I should be able to rule it out, right? Roommate No. 2 Xu Qinsi: A social terrorist who always likes to touch me every day. I used to think this was sisterly love, but now I'm beginning to suspect she's taking advantage of it! Roommate No. 3 Su Yu: Her? Just say a word to her and she'll blush till she's smoking. It's very suspicious, but she would be so nervous that she would faint even if she looked at me. Can she really withstand the psychological pressure of committing a crime? Roommate No. 4 Chen Jianhuan: This person is a very humorous woman with a louder voice than my mother. Logically speaking, she is the most unlikely person because she can't hide any secrets at all. But what if... What if this is her cover? So I decided to investigate the case myself. Clingy, probing... I used all the tricks I could. It turned out that everyone seemed to have problems, and no one seemed to have any problems. But who am I, Shen Lulu? Will I give up? No matter who you are—— Me! All! One! Certainly! Want! Bundle! You! Pull! Out! Come!