Hello, looking for a manga that I think is yaoi or shounen ai.
The only scene I remember us a guy being called out by a female classmate with short black hair.
When they are outside the girl lifts her skirt and say that she is sorry,
underneath her skirt is a dagger straped to her thigh.
Her father is in some debt I think and she tries to kill him.
As I read 100% slashable/yaoi Im pretty sure this one is also at least shounen ai.
Thanks :-)

I know it is from Hoshino Lily, but I don't quite remember which one.
Edit: it's in Hanayome-kun, called "even if it costs me my life".