Spoiler-not-spoiler:
Hayan is not a cisfem, she's a trans. MTF She has nothing to do with the dead friend (they have different physique). When she said "I should", that's because she hoped she was born in a girl's body, hence the "crossdressing" part. She was accused for being a pervert for "cosplaying" as a girl.
But the whole thing was ruined by the progression of the story. What a waste u_u