|It's been over 2 years... so, I'll be fuzzy on the details...
Spoiler (highlight to view)
All I remember is that her mentor, the blond/white haired dude, is the murderer, and he only did it to have someone he could compete against; since, the trauma of the event would scar her for life... making her strive to meet her parents' murderer. As for what else might have disappointed me... I believe the actual story/acting/portrayal of the whole ending was subpar.
Otherwise, it was just lame ending.
To me, it seemed like another inane shounen series... not a Seinen.
And a half-assed thriller story at that.
"Officially, this machine doesn't exist, you didn't get it from me,
and I don't know you. Make sure it doesn't leave the building."