Step 1. Notice how she appears so gracefully as she walks by your table like this
Step 2.Notice in this picture I found you look like you’re about to have a heart attack.
That means you’re in the yandere route and there is no escape. Basically you are screwed.
Step 3. Rape.
Step 4. You either die or look like this guy
And that;s how you meet a yandere … or at least in this anime