......No, I'm pretty sure she ends up with the yandere? If they reveal his gender so fast but doesn't reveal his background info, then he's usually the ML. It's definitely not the blonde guy, I think the ML is Yuri.
I'm really basing this off of cliches and the fact that the author is trying to sell the "yandere" tag here
Heh.. here im 100% she gonna end up with yandere. Not with that blondie womanizer ┑(￣Д ￣)┍
Bruh, I know yandere stories are predictable and all... so I know Sian isn’t going to end up with Yuri but god damn do I wish she does end up with our cross dressing yandere boy here
50/50 shot in her ending up with blonde dude just because he was “nice” to her. Even though I know this, imma still eat my shoe from anger. #LetYanderesHaveHappyEndingsToo2020