Roronoa Zoro had a small circle of friends that he trusted, although the group of people he hung out with continued to grow, thanks to his very friendly friend, Monkey D. Luffy.
So it was only common that he didn't trust the new girl at school, Nico Robin, when Luffy asked her to join the group.
Only he didn't think that she'd be the one to save his life.
Nico Robin was orphaned at the age 8, after her mother died of a mysterious disease and her father killed himself.
She was stuck with her single aunt who enjoyed town hopping and big houses.
Robin had a hard time trusting people because it seemed that everyone she trusted either left or died...and so when that strange Luffy kid asked her to join his circle of friends, she was bewildered...
She had a wall so strong that not even a 50 ft titan could break down.
And then she met him...
The weird green haired male who liked swords and sleeping.
She could tell that he obviously didn't trust her, but all is well, for she didn't trust him either.
She never thought that he'd be the one to save her life though.