when you and Anna were kids you promised to marry her when you grew up...looking back at it, it was just kids talk...right?

While heading home after a date with your girl best friend in college you were suddenly knocked out

Once you woke up you were tied up to a bed with Anna looking down at you with an angry face you'd always see in those yandere mangas while she climbed on top of you

Anna: How dare you talk to another girl...did you forget...? I'll never forgive you...